83 files changed, 5590 insertions, 1163 deletions
diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
new file mode 100644
index 0000000..f76baff
--- /dev/null
+++ b/.github/FUNDING.yml
@@ -0,0 +1 @@
+tidelift: "pypi/pytz"
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..4f25569
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,38 @@
+name: Tests
+
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: ["2.7", "3.5", "3.6", "3.7", "3.8", "3.9", "3.10"]
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip wheel flake8
+      - name: Build
+        run: |
+          make build
+      - name: Unit Tests
+        run: |
+          cd build/dist/pytz/tests
+          python test_lazy.py -vv
+          python test_tzinfo.py -vv
+      - name: Documentation Tests
+        run: |
+          cd build/dist/pytz/tests
+          python test_docs.py -vv
+      - name: zdump Tests
+        if: ${{ matrix.python-version == '3.10' }}
+        run: |
+          python gen_tests.py
+          python test_zdump.py -vv
diff --git a/.gitignore b/.gitignore
index cf3b825..725ae92 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,26 +1,13 @@
-# Files intentionally not tracked by Git.
-# This file is in the public domain.
-*.a
-*.asc
-*.diff
-*.i
-*.o
-*.orig
-*.patch
-*.rej
-*.tar
-*.tar.*
-*.txt
-*.tzs
-*.zi
 *~
-ChangeLog
-check_*
-date
-leapseconds
-tzselect
-version
-version.h
-yearistype
-zdump
-zic
+*.py[co]
+
+# Build-related files
+.stamp-dist
+.stamp-tzinfo
+.stamp-zoneinfo
+# For whatever reason, build/ is versioned, so the * is necessary.
+build/*
+tz/version
+
+# Generated datafile for test_zdump.py
+zdump.out
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..532b224
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,44 @@
+# vim: set filetype=yaml sw=2:
+sudo: required
+dist: bionic
+addons:
+  apt:
+    sources:
+      - deadsnakes
+    update: true
+    packages:
+      - wget
+      - build-essential
+      - python-all
+      - python-all-dev
+      - python-setuptools
+      - python-pip
+      - python-wheel
+      - python-flake8
+      - python3-all
+      - python3-all-dev
+      - python3-setuptools
+      - python3-pip
+      - python3-wheel
+      - python3-flake8
+      - python3-docutils
+      - python3-sphinx
+      - python2.4-complete
+      - python2.4-gdbm
+      - python2.4-gdbm-dbg
+      - python2.5-complete
+      - python2.6-complete
+      - python3.1-complete
+      - python3.2-complete
+      - python3.3-complete
+      - python3.4-complete
+      - python3.5-complete
+      - python3.6
+      - python3.7
+      - python3.7-dev
+      - python3.8
+      - python3.8-dev
+      - python3.9
+      - python3.9-dev
+install: true
+script: make test TESTARGS=
diff --git a/LICENSE.txt b/LICENSE.txt
new file mode 100644
index 0000000..5f1c112
--- /dev/null
+++ b/LICENSE.txt
@@ -0,0 +1,19 @@
+Copyright (c) 2003-2019 Stuart Bishop <stuart@stuartbishop.net>
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/Makefile b/Makefile
index a9a989e..ac6f43c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,1146 +1,190 @@
-# Make and install tzdb code and data.
-
-# This file is in the public domain, so clarified as of
-# 2009-05-17 by Arthur David Olson.
-
-# Package name for the code distribution.
-PACKAGE=	tzcode
-
-# Version number for the distribution, overridden in the 'tarballs' rule below.
-VERSION=	unknown
-
-# Email address for bug reports.
-BUGEMAIL=	tz@iana.org
-
-# DATAFORM selects the data format.
-# Available formats represent essentially the same data, albeit
-# possibly with minor discrepancies that users are not likely to notice.
-# To get new features and the best data right away, use:
-#	DATAFORM=	vanguard
-# To wait a while before using new features, to give downstream users
-# time to upgrade zic (the default), use:
-#	DATAFORM=	main
-# To wait even longer for new features, use:
-#	DATAFORM=	rearguard
-# Rearguard users might also want "ZFLAGS = -b fat"; see below.
-DATAFORM=		main
-
-# Change the line below for your timezone (after finding the one you want in
-# one of the $(TDATA) source files, or adding it to a source file).
-# Alternatively, if you discover you've got the wrong timezone, you can just
-# 'zic -l -' to remove it, or 'zic -l rightzone' to change it.
-# Use the command
-#	make zonenames
-# to get a list of the values you can use for LOCALTIME.
-
-LOCALTIME=	GMT
-
-# The POSIXRULES macro controls interpretation of nonstandard and obsolete
-# POSIX-like TZ settings like TZ='EET-2EEST' that lack DST transition rules.
-# Such a setting uses the rules in a template file to determine
-# "spring forward" and "fall back" days and times; the environment
-# variable itself specifies UT offsets of standard and daylight saving time.
-#
-# If POSIXRULES is '-', no template is installed; this is the default.
+# Build the pytz libraries
 #
-# Any other value for POSIXRULES is obsolete and should not be relied on, as:
-# * It does not work correctly in popular implementations such as GNU/Linux.
-# * It does not work even in tzcode, except for historical timestamps
-#   that precede the last explicit transition in the POSIXRULES file.
-#   Hence it typically does not work for current and future timestamps.
-# In short, software should avoid ruleless settings like TZ='EET-2EEST'
-# and so should not depend on the value of POSIXRULES.
-#
-# If, despite the above, you want a template for handling these settings,
-# you can change the line below (after finding the timezone you want in the
-# one of the $(TDATA) source files, or adding it to a source file).
-# Alternatively, if you discover you've got the wrong timezone, you can just
-# 'zic -p -' to remove it, or 'zic -p rightzone' to change it.
-# Use the command
-#	make zonenames
-# to get a list of the values you can use for POSIXRULES.
-
-POSIXRULES=	-
-
-# Also see TZDEFRULESTRING below, which takes effect only
-# if the time zone files cannot be accessed.
-
-
-# Installation locations.
-#
-# The defaults are suitable for Debian, except that if REDO is
-# posix_right or right_posix then files that Debian puts under
-# /usr/share/zoneinfo/posix and /usr/share/zoneinfo/right are instead
-# put under /usr/share/zoneinfo-posix and /usr/share/zoneinfo-leaps,
-# respectively.  Problems with the Debian approach are discussed in
-# the commentary for the right_posix rule (below).
-
-# Destination directory, which can be used for staging.
-# 'make DESTDIR=/stage install' installs under /stage (e.g., to
-# /stage/etc/localtime instead of to /etc/localtime).  Files under
-# /stage are not intended to work as-is, but can be copied by hand to
-# the root directory later.  If DESTDIR is empty, 'make install' does
-# not stage, but installs directly into production locations.
-DESTDIR =
-
-# Everything is installed into subdirectories of TOPDIR, and used there.
-# TOPDIR should be empty (meaning the root directory),
-# or a directory name that does not end in "/".
-# TOPDIR should be empty or an absolute name unless you're just testing.
-TOPDIR =
-
-# The default local timezone is taken from the file TZDEFAULT.
-TZDEFAULT = $(TOPDIR)/etc/localtime
-
-# The subdirectory containing installed program and data files, and
-# likewise for installed files that can be shared among architectures.
-# These should be relative file names.
-USRDIR = usr
-USRSHAREDIR = $(USRDIR)/share
-
-# "Compiled" timezone information is placed in the "TZDIR" directory
-# (and subdirectories).
-# TZDIR_BASENAME should not contain "/" and should not be ".", ".." or empty.
-TZDIR_BASENAME=	zoneinfo
-TZDIR = $(TOPDIR)/$(USRSHAREDIR)/$(TZDIR_BASENAME)
-
-# The "tzselect" and (if you do "make INSTALL") "date" commands go in:
-BINDIR = $(TOPDIR)/$(USRDIR)/bin
-
-# The "zdump" command goes in:
-ZDUMPDIR = $(BINDIR)
-
-# The "zic" command goes in:
-ZICDIR = $(TOPDIR)/$(USRDIR)/sbin
-
-# Manual pages go in subdirectories of. . .
-MANDIR = $(TOPDIR)/$(USRSHAREDIR)/man
-
-# Library functions are put in an archive in LIBDIR.
-LIBDIR = $(TOPDIR)/$(USRDIR)/lib
-
-
-# Types to try, as an alternative to time_t.
-TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL)
-TIME_T_ALTERNATIVES_HEAD = int_least64_t
-TIME_T_ALTERNATIVES_TAIL = int_least32_t uint_least32_t uint_least64_t
-
-# What kind of TZif data files to generate.  (TZif is the binary time
-# zone data format that zic generates; see Internet RFC 8536.)
-# If you want only POSIX time, with time values interpreted as
-# seconds since the epoch (not counting leap seconds), use
-#	REDO=		posix_only
-# below.  If you want only "right" time, with values interpreted
-# as seconds since the epoch (counting leap seconds), use
-#	REDO=		right_only
-# below.  If you want both sets of data available, with leap seconds not
-# counted normally, use
-#	REDO=		posix_right
-# below.  If you want both sets of data available, with leap seconds counted
-# normally, use
-#	REDO=		right_posix
-# below.  POSIX mandates that leap seconds not be counted; for compatibility
-# with it, use "posix_only" or "posix_right".  Use POSIX time on systems with
-# leap smearing; this can work better than unsmeared "right" time with
-# applications that are not leap second aware, and is closer to unsmeared
-# "right" time than unsmeared POSIX time is (e.g., 0.5 vs 1.0 s max error).
-
-REDO=		posix_right
-
-# Whether to put an "Expires" line in the leapseconds file.
-# Use EXPIRES_LINE=1 to put the line in, 0 to omit it.
-# The EXPIRES_LINE value matters only if REDO's value contains "right".
-# If you change EXPIRES_LINE, remove the leapseconds file before running "make".
-# zic's support for the Expires line was introduced in tzdb 2020a,
-# and was modified in tzdb 2021b to generate version 4 TZif files.
-# EXPIRES_LINE defaults to 0 for now so that the leapseconds file
-# can be given to pre-2020a zic implementations and so that TZif files
-# built by newer zic implementations can be read by pre-2021b libraries.
-EXPIRES_LINE=	0
-
-# To install data in text form that has all the information of the TZif data,
-# (optionally incorporating leap second information), use
-#	TZDATA_TEXT=	tzdata.zi leapseconds
-# To install text data without leap second information (e.g., because
-# REDO='posix_only'), use
-#	TZDATA_TEXT=	tzdata.zi
-# To avoid installing text data, use
-#	TZDATA_TEXT=
-
-TZDATA_TEXT=	leapseconds tzdata.zi
-
-# For backward-compatibility links for old zone names, use
-#	BACKWARD=	backward
-# To omit these links, use
-#	BACKWARD=
-
-BACKWARD=	backward
-
-# If you want out-of-scope and often-wrong data from the file 'backzone', use
-#	PACKRATDATA=	backzone
-# To omit this data, use
-#	PACKRATDATA=
-
-PACKRATDATA=
-
-# The name of a locale using the UTF-8 encoding, used during self-tests.
-# The tests are skipped if the name does not appear to work on this system.
-
-UTF8_LOCALE=	en_US.utf8
-
-# Non-default libraries needed to link.
-LDLIBS=
-
-# Add the following to the end of the "CFLAGS=" line as needed to override
-# defaults specified in the source code.  "-DFOO" is equivalent to "-DFOO=1".
-#  -DDEPRECATE_TWO_DIGIT_YEARS for optional runtime warnings about strftime
-#	formats that generate only the last two digits of year numbers
-#  -DEPOCH_LOCAL if the 'time' function returns local time not UT
-#  -DEPOCH_OFFSET=N if the 'time' function returns a value N greater
-#	than what POSIX specifies, assuming local time is UT.
-#	For example, N is 252460800 on AmigaOS.
-#  -DHAVE_DECL_ASCTIME_R=0 if <time.h> does not declare asctime_r
-#  -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ'
-#  -DHAVE_DIRECT_H if mkdir needs <direct.h> (MS-Windows)
-#  -DHAVE_GENERIC=0 if _Generic does not work
-#  -DHAVE_GETTEXT if 'gettext' works (e.g., GNU/Linux, FreeBSD, Solaris)
-#  -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares
-#	ctime_r and asctime_r incompatibly with the POSIX standard
-#	(Solaris when _POSIX_PTHREAD_SEMANTICS is not defined).
-#  -DHAVE_INTTYPES_H if you have a non-C99 compiler with <inttypes.h>
-#  -DHAVE_LINK=0 if your system lacks a link function
-#  -DHAVE_LOCALTIME_R=0 if your system lacks a localtime_r function
-#  -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz
-#	localtime_rz can make zdump significantly faster, but is nonstandard.
-#  -DHAVE_MALLOC_ERRNO=0 if malloc etc. do not set errno on failure.
-#  -DHAVE_POSIX_DECLS=0 if your system's include files do not declare
-#	functions like 'link' or variables like 'tzname' required by POSIX
-#  -DHAVE_SNPRINTF=0 if your system lacks the snprintf function
-#  -DHAVE_STDBOOL_H if you have a non-C99 compiler with <stdbool.h>
-#  -DHAVE_STDINT_H if you have a non-C99 compiler with <stdint.h>
-#  -DHAVE_STRFTIME_L if <time.h> declares locale_t and strftime_l
-#  -DHAVE_STRDUP=0 if your system lacks the strdup function
-#  -DHAVE_STRTOLL=0 if your system lacks the strtoll function
-#  -DHAVE_SYMLINK=0 if your system lacks the symlink function
-#  -DHAVE_SYS_STAT_H=0 if your compiler lacks a <sys/stat.h>
-#  -DHAVE_TZSET=0 if your system lacks a tzset function
-#  -DHAVE_UNISTD_H=0 if your compiler lacks a <unistd.h>
-#  -Dlocale_t=XXX if your system uses XXX instead of locale_t
-#  -DRESERVE_STD_EXT_IDS if your platform reserves standard identifiers
-#	with external linkage, e.g., applications cannot define 'localtime'.
-#  -Dssize_t=long on hosts like MS-Windows that lack ssize_t
-#  -DSUPPRESS_TZDIR to not prepend TZDIR to file names; this has
-#	security implications and is not recommended for general use
-#  -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires;
-#	not needed by the main-program tz code, which is single-threaded.
-#	Append other compiler flags as needed, e.g., -pthread on GNU/Linux.
-#  -Dtime_tz=\"T\" to use T as the time_t type, rather than the system time_t
-#	This is intended for internal use only; it mangles external names.
-#  -DTZ_DOMAIN=\"foo\" to use "foo" for gettext domain name; default is "tz"
-#  -DTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory;
-#	the default is system-supplied, typically "/usr/lib/locale"
-#  -DTZDEFRULESTRING=\",date/time,date/time\" to default to the specified
-#	DST transitions if the time zone files cannot be accessed
-#  -DUNINIT_TRAP if reading uninitialized storage can cause problems
-#	other than simply getting garbage data
-#  -DUSE_LTZ=0 to build zdump with the system time zone library
-#	Also set TZDOBJS=zdump.o and CHECK_TIME_T_ALTERNATIVES= below.
-#  -DZIC_BLOAT_DEFAULT=\"fat\" to default zic's -b option to "fat", and
-#	similarly for "slim".  Fat TZif files work around incompatibilities
-#	and bugs in some TZif readers, notably readers that mishandle 64-bit
-#	data in TZif files.  Slim TZif files are more efficient and do not
-#	work around these incompatibilities and bugs.  If not given, the
-#	default is "slim".
-#  -DZIC_MAX_ABBR_LEN_WO_WARN=3
-#	(or some other number) to set the maximum time zone abbreviation length
-#	that zic will accept without a warning (the default is 6)
-#  $(GCC_DEBUG_FLAGS) if you are using recent GCC and want lots of checking
-# Select instrumentation via "make GCC_INSTRUMENT='whatever'".
-GCC_INSTRUMENT = \
-  -fsanitize=undefined -fsanitize-address-use-after-scope \
-  -fsanitize-undefined-trap-on-error -fstack-protector
-# Omit -fanalyzer from GCC_DEBUG_FLAGS, as it makes GCC too slow.
-GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
-  $(GCC_INSTRUMENT) \
-  -Wall -Wextra \
-  -Walloc-size-larger-than=100000 -Warray-bounds=2 \
-  -Wbad-function-cast -Wcast-align=strict -Wdate-time \
-  -Wdeclaration-after-statement -Wdouble-promotion \
-  -Wduplicated-branches -Wduplicated-cond \
-  -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \
-  -Winit-self -Wlogical-op \
-  -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \
-  -Wnull-dereference \
-  -Wold-style-definition -Woverlength-strings -Wpointer-arith \
-  -Wshadow -Wshift-overflow=2 -Wstrict-overflow \
-  -Wstrict-prototypes -Wstringop-overflow=4 \
-  -Wstringop-truncation -Wsuggest-attribute=cold \
-  -Wsuggest-attribute=const -Wsuggest-attribute=format \
-  -Wsuggest-attribute=malloc \
-  -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \
-  -Wtrampolines -Wundef -Wuninitialized -Wunused-macros \
-  -Wvariadic-macros -Wvla -Wwrite-strings \
-  -Wno-address -Wno-format-nonliteral -Wno-sign-compare \
-  -Wno-type-limits -Wno-unused-parameter
-#
-# If your system has a "GMT offset" field in its "struct tm"s
-# (or if you decide to add such a field in your system's "time.h" file),
-# add the name to a define such as
-#	-DTM_GMTOFF=tm_gmtoff
-# to the end of the "CFLAGS=" line.  If not defined, the code attempts to
-# guess TM_GMTOFF from other macros; define NO_TM_GMTOFF to suppress this.
-# Similarly, if your system has a "zone abbreviation" field, define
-#	-DTM_ZONE=tm_zone
-# and define NO_TM_ZONE to suppress any guessing.  These two fields are not
-# required by POSIX, but are widely available on GNU/Linux and BSD systems.
-#
-# The next batch of options control support for external variables
-# exported by tzcode.  In practice these variables are less useful
-# than TM_GMTOFF and TM_ZONE.  However, most of them are standardized.
-# #
-# # To omit or support the external variable "tzname", add one of:
-# #	-DHAVE_TZNAME=0 # do not support "tzname"
-# #	-DHAVE_TZNAME=1 # support "tzname", which is defined by system library
-# #	-DHAVE_TZNAME=2 # support and define "tzname"
-# # to the "CFLAGS=" line.  "tzname" is required by POSIX 1988 and later.
-# # If not defined, the code attempts to guess HAVE_TZNAME from other macros.
-# # Warning: unless time_tz is also defined, HAVE_TZNAME=1 can cause
-# # crashes when combined with some platforms' standard libraries,
-# # presumably due to memory allocation issues.
-# #
-# # To omit or support the external variables "timezone" and "daylight", add
-# #	-DUSG_COMPAT=0 # do not support
-# #	-DUSG_COMPAT=1 # support, and variables are defined by system library
-# #	-DUSG_COMPAT=2 # support and define variables
-# # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by
-# # Unix Systems Group code and are required by POSIX 2008 (with XSI) and later.
-# # If not defined, the code attempts to guess USG_COMPAT from other macros.
-# #
-# # To support the external variable "altzone", add
-# #	-DALTZONE=0 # do not support
-# #	-DALTZONE=1 # support "altzone", which is defined by system library
-# #	-DALTZONE=2 # support and define "altzone"
-# # to the end of the "CFLAGS=" line; although "altzone" appeared in
-# # System V Release 3.1 it has not been standardized.
-# # If not defined, the code attempts to guess ALTZONE from other macros.
-#
-# If you want functions that were inspired by early versions of X3J11's work,
-# add
-#	-DSTD_INSPIRED
-# to the end of the "CFLAGS=" line.  This arranges for the functions
-# "offtime", "timelocal", "timegm", "timeoff",
-# "posix2time", and "time2posix" to be added to the time conversion library.
-# "offtime" is like "gmtime" except that it accepts a second (long) argument
-# that gives an offset to add to the time_t when converting it.
-# "timelocal" is equivalent to "mktime".
-# "timegm" is like "timelocal" except that it turns a struct tm into
-# a time_t using UT (rather than local time as "timelocal" does).
-# "timeoff" is like "timegm" except that it accepts a second (long) argument
-# that gives an offset to use when converting to a time_t.
-# "posix2time" and "time2posix" are described in an included manual page.
-# X3J11's work does not describe any of these functions.
-# These functions may well disappear in future releases of the time
-# conversion package.
-#
-# If you don't want functions that were inspired by NetBSD, add
-#	-DNETBSD_INSPIRED=0
-# to the end of the "CFLAGS=" line.  Otherwise, the functions
-# "localtime_rz", "mktime_z", "tzalloc", and "tzfree" are added to the
-# time library, and if STD_INSPIRED is also defined the functions
-# "posix2time_z" and "time2posix_z" are added as well.
-# The functions ending in "_z" (or "_rz") are like their unsuffixed
-# (or suffixed-by-"_r") counterparts, except with an extra first
-# argument of opaque type timezone_t that specifies the timezone.
-# "tzalloc" allocates a timezone_t value, and "tzfree" frees it.
-#
-# If you want to allocate state structures in localtime, add
-#	-DALL_STATE
-# to the end of the "CFLAGS=" line.  Storage is obtained by calling malloc.
-#
-# NIST-PCTS:151-2, Version 1.4, (1993-12-03) is a test suite put
-# out by the National Institute of Standards and Technology
-# which claims to test C and Posix conformance.  If you want to pass PCTS, add
-#	-DPCTS
-# to the end of the "CFLAGS=" line.
-#
-# If you want strict compliance with XPG4 as of 1994-04-09, add
-#	-DXPG4_1994_04_09
-# to the end of the "CFLAGS=" line.  This causes "strftime" to always return
-# 53 as a week number (rather than 52 or 53) for January days before
-# January's first Monday when a "%V" format is used and January 1
-# falls on a Friday, Saturday, or Sunday.
-
-CFLAGS=
-
-# Linker flags.  Default to $(LFLAGS) for backwards compatibility
-# to release 2012h and earlier.
-
-LDFLAGS=	$(LFLAGS)
-
-# For leap seconds, this Makefile uses LEAPSECONDS='-L leapseconds' in
-# submake command lines.  The default is no leap seconds.
-
-LEAPSECONDS=
-
-# The zic command and its arguments.
-
-zic=		./zic
-ZIC=		$(zic) $(ZFLAGS)
-
-# To shrink the size of installed TZif files,
-# append "-r @N" to omit data before N-seconds-after-the-Epoch.
-# To grow the files and work around older application bugs, append "-b fat";
-# see ZIC_BLOAT_DEFAULT above.
-# See the zic man page for more about -b and -r.
-ZFLAGS=
-
-# How to use zic to install TZif files.
-
-ZIC_INSTALL=	$(ZIC) -d '$(DESTDIR)$(TZDIR)' $(LEAPSECONDS)
-
-# The name of a Posix-compliant 'awk' on your system.
-# mawk 1.3.3 and Solaris 10 /usr/bin/awk do not work.
-# Also, it is better (though not essential) if 'awk' supports UTF-8,
-# and unfortunately mawk and busybox awk do not support UTF-8.
-# Try AWK=gawk or AWK=nawk if your awk has the abovementioned problems.
-AWK=		awk
-
-# The full path name of a Posix-compliant shell, preferably one that supports
-# the Korn shell's 'select' statement as an extension.
-# These days, Bash is the most popular.
-# It should be OK to set this to /bin/sh, on platforms where /bin/sh
-# lacks 'select' or doesn't completely conform to Posix, but /bin/bash
-# is typically nicer if it works.
-KSHELL=		/bin/bash
-
-# Name of curl <https://curl.haxx.se/>, used for HTML validation.
-CURL=		curl
-
-# Name of GNU Privacy Guard <https://gnupg.org/>, used to sign distributions.
-GPG=		gpg
-
-# This expensive test requires USE_LTZ.
-# To suppress it, define this macro to be empty.
-CHECK_TIME_T_ALTERNATIVES = check_time_t_alternatives
-
-# SAFE_CHAR is a regular expression that matches a safe character.
-# Some parts of this distribution are limited to safe characters;
-# others can use any UTF-8 character.
-# For now, the safe characters are a safe subset of ASCII.
-# The caller must set the shell variable 'sharp' to the character '#',
-# since Makefile macros cannot contain '#'.
-# TAB_CHAR is a single tab character, in single quotes.
-TAB_CHAR=	'	'
-SAFE_CHARSET1=	$(TAB_CHAR)' !\"'$$sharp'$$%&'\''()*+,./0123456789:;<=>?@'
-SAFE_CHARSET2=	'ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\^_`'
-SAFE_CHARSET3=	'abcdefghijklmnopqrstuvwxyz{|}~'
-SAFE_CHARSET=	$(SAFE_CHARSET1)$(SAFE_CHARSET2)$(SAFE_CHARSET3)
-SAFE_CHAR=	'[]'$(SAFE_CHARSET)'-]'
-
-# These characters are Latin-1, and so are likely to be displayable
-# even in editors with limited character sets.
-UNUSUAL_OK_LATIN_1 = «°±»½¾×
-# This IPA symbol is represented in Unicode as the composition of
-# U+0075 and U+032F, and U+032F is not considered alphabetic by some
-# grep implementations that do not grok composition.
-UNUSUAL_OK_IPA = u̯
-# Non-ASCII non-letters that OK_CHAR allows, as these characters are
-# useful in commentary.
-UNUSUAL_OK_CHARSET= $(UNUSUAL_OK_LATIN_1)$(UNUSUAL_OK_IPA)
-
-# OK_CHAR matches any character allowed in the distributed files.
-# This is the same as SAFE_CHAR, except that UNUSUAL_OK_CHARSET and
-# multibyte letters are also allowed so that commentary can contain a
-# few safe symbols and people's names and can quote non-English sources.
-# Other non-letters are limited to ASCII renderings for the
-# convenience of maintainers using XEmacs 21.5.34, which by default
-# mishandles Unicode characters U+0100 and greater.
-OK_CHAR=	'[][:alpha:]$(UNUSUAL_OK_CHARSET)'$(SAFE_CHARSET)'-]'
-
-# SAFE_LINE matches a line of safe characters.
-# SAFE_SHARP_LINE is similar, except any OK character can follow '#';
-# this is so that comments can contain non-ASCII characters.
-# OK_LINE matches a line of OK characters.
-SAFE_LINE=	'^'$(SAFE_CHAR)'*$$'
-SAFE_SHARP_LINE='^'$(SAFE_CHAR)'*('$$sharp$(OK_CHAR)'*)?$$'
-OK_LINE=	'^'$(OK_CHAR)'*$$'
-
-# Flags to give 'tar' when making a distribution.
-# Try to use flags appropriate for GNU tar.
-GNUTARFLAGS= --format=pax --pax-option='delete=atime,delete=ctime' \
-  --numeric-owner --owner=0 --group=0 \
-  --mode=go+u,go-w --sort=name
-TARFLAGS=	`if tar $(GNUTARFLAGS) --version >/dev/null 2>&1; \
-		 then echo $(GNUTARFLAGS); \
-		 else :; \
-		 fi`
 
-# Flags to give 'gzip' when making a distribution.
-GZIPFLAGS=	-9n
-
-###############################################################################
-
-#MAKE=		make
-
-cc=		cc
-CC=		$(cc) -DTZDIR='"$(TZDIR)"'
-
-AR=		ar
-
-# ':' on typical hosts; 'ranlib' on the ancient hosts that still need ranlib.
-RANLIB=		:
-
-TZCOBJS=	zic.o
-TZDOBJS=	zdump.o localtime.o asctime.o strftime.o
-DATEOBJS=	date.o localtime.o strftime.o asctime.o
-LIBSRCS=	localtime.c asctime.c difftime.c strftime.c
-LIBOBJS=	localtime.o asctime.o difftime.o strftime.o
-HEADERS=	tzfile.h private.h
-NONLIBSRCS=	zic.c zdump.c
-NEWUCBSRCS=	date.c
-SOURCES=	$(HEADERS) $(LIBSRCS) $(NONLIBSRCS) $(NEWUCBSRCS) \
-			tzselect.ksh workman.sh
-MANS=		newctime.3 newstrftime.3 newtzset.3 time2posix.3 \
-			tzfile.5 tzselect.8 zic.8 zdump.8
-MANTXTS=	newctime.3.txt newstrftime.3.txt newtzset.3.txt \
-			time2posix.3.txt \
-			tzfile.5.txt tzselect.8.txt zic.8.txt zdump.8.txt \
-			date.1.txt
-COMMON=		calendars CONTRIBUTING LICENSE Makefile \
-			NEWS README SECURITY theory.html version
-WEB_PAGES=	tz-art.html tz-how-to.html tz-link.html
-CHECK_WEB_PAGES=check_theory.html check_tz-art.html \
-			check_tz-how-to.html check_tz-link.html
-DOCS=		$(MANS) date.1 $(MANTXTS) $(WEB_PAGES)
-PRIMARY_YDATA=	africa antarctica asia australasia \
-		europe northamerica southamerica
-YDATA=		$(PRIMARY_YDATA) etcetera
-NDATA=		factory
-TDATA_TO_CHECK=	$(YDATA) $(NDATA) backward
-TDATA=		$(YDATA) $(NDATA) $(BACKWARD)
-ZONETABLES=	zone1970.tab zone.tab
-TABDATA=	iso3166.tab $(TZDATA_TEXT) $(ZONETABLES)
-LEAP_DEPS=	leapseconds.awk leap-seconds.list
-TZDATA_ZI_DEPS=	ziguard.awk zishrink.awk version $(TDATA) $(PACKRATDATA)
-DSTDATA_ZI_DEPS= ziguard.awk $(TDATA) $(PACKRATDATA)
-DATA=		$(TDATA_TO_CHECK) backzone iso3166.tab leap-seconds.list \
-			leapseconds $(ZONETABLES)
-AWK_SCRIPTS=	checklinks.awk checktab.awk leapseconds.awk \
-			ziguard.awk zishrink.awk
-MISC=		$(AWK_SCRIPTS) zoneinfo2tdf.pl
-TZS_YEAR=	2050
-TZS_CUTOFF_FLAG=	-c $(TZS_YEAR)
-TZS=		to$(TZS_YEAR).tzs
-TZS_NEW=	to$(TZS_YEAR)new.tzs
-TZS_DEPS=	$(YDATA) asctime.c localtime.c \
-			private.h tzfile.h zdump.c zic.c
-# EIGHT_YARDS is just a yard short of the whole ENCHILADA.
-EIGHT_YARDS = $(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) tzdata.zi
-ENCHILADA = $(EIGHT_YARDS) $(TZS)
-
-# Consult these files when deciding whether to rebuild the 'version' file.
-# This list is not the same as the output of 'git ls-files', since
-# .gitignore is not distributed.
-VERSION_DEPS= \
-		calendars CONTRIBUTING LICENSE Makefile NEWS README SECURITY \
-		africa antarctica asctime.c asia australasia \
-		backward backzone \
-		checklinks.awk checktab.awk \
-		date.1 date.c difftime.c \
-		etcetera europe factory iso3166.tab \
-		leap-seconds.list leapseconds.awk localtime.c \
-		newctime.3 newstrftime.3 newtzset.3 northamerica \
-		private.h southamerica strftime.c theory.html \
-		time2posix.3 tz-art.html tz-how-to.html tz-link.html \
-		tzfile.5 tzfile.h tzselect.8 tzselect.ksh \
-		workman.sh zdump.8 zdump.c zic.8 zic.c \
-		ziguard.awk zishrink.awk \
-		zone.tab zone1970.tab zoneinfo2tdf.pl
-
-# And for the benefit of csh users on systems that assume the user
-# shell should be used to handle commands in Makefiles. . .
-
-SHELL=		/bin/sh
-
-all:		tzselect zic zdump libtz.a $(TABDATA) \
-		  vanguard.zi main.zi rearguard.zi
-
-ALL:		all date $(ENCHILADA)
-
-install:	all $(DATA) $(REDO) $(MANS)
-		mkdir -p '$(DESTDIR)$(BINDIR)' \
-			'$(DESTDIR)$(ZDUMPDIR)' '$(DESTDIR)$(ZICDIR)' \
-			'$(DESTDIR)$(LIBDIR)' \
-			'$(DESTDIR)$(MANDIR)/man3' '$(DESTDIR)$(MANDIR)/man5' \
-			'$(DESTDIR)$(MANDIR)/man8'
-		$(ZIC_INSTALL) -l $(LOCALTIME) \
-			`case '$(POSIXRULES)' in ?*) echo '-p';; esac \
-			` $(POSIXRULES) \
-			-t '$(DESTDIR)$(TZDEFAULT)'
-		cp -f $(TABDATA) '$(DESTDIR)$(TZDIR)/.'
-		cp tzselect '$(DESTDIR)$(BINDIR)/.'
-		cp zdump '$(DESTDIR)$(ZDUMPDIR)/.'
-		cp zic '$(DESTDIR)$(ZICDIR)/.'
-		cp libtz.a '$(DESTDIR)$(LIBDIR)/.'
-		$(RANLIB) '$(DESTDIR)$(LIBDIR)/libtz.a'
-		cp -f newctime.3 newtzset.3 '$(DESTDIR)$(MANDIR)/man3/.'
-		cp -f tzfile.5 '$(DESTDIR)$(MANDIR)/man5/.'
-		cp -f tzselect.8 zdump.8 zic.8 '$(DESTDIR)$(MANDIR)/man8/.'
-
-INSTALL:	ALL install date.1
-		mkdir -p '$(DESTDIR)$(BINDIR)' '$(DESTDIR)$(MANDIR)/man1'
-		cp date '$(DESTDIR)$(BINDIR)/.'
-		cp -f date.1 '$(DESTDIR)$(MANDIR)/man1/.'
-
-# Calculate version number from git, if available.
-# Otherwise, use $(VERSION) unless it is "unknown" and there is already
-# a 'version' file, in which case reuse the existing 'version' contents
-# and append "-dirty" if the contents do not already end in "-dirty".
-version:	$(VERSION_DEPS)
-		{ (type git) >/dev/null 2>&1 && \
-		  V=`git describe --match '[0-9][0-9][0-9][0-9][a-z]*' \
-				--abbrev=7 --dirty` || \
-		  if test '$(VERSION)' = unknown && V=`cat $@`; then \
-		    case $$V in *-dirty);; *) V=$$V-dirty;; esac; \
-		  else \
-		    V='$(VERSION)'; \
-		  fi; } && \
-		printf '%s\n' "$$V" >$@.out
-		mv $@.out $@
-
-# These files can be tailored by setting BACKWARD and PACKRATDATA.
-vanguard.zi main.zi rearguard.zi: $(DSTDATA_ZI_DEPS)
-		$(AWK) -v DATAFORM=`expr $@ : '\(.*\).zi'` -f ziguard.awk \
-		  $(TDATA) $(PACKRATDATA) >$@.out
-		mv $@.out $@
-# This file has a version comment that attempts to capture any tailoring
-# via BACKWARD, DATAFORM, PACKRATDATA, and REDO.
-tzdata.zi:	$(DATAFORM).zi version zishrink.awk
-		version=`sed 1q version` && \
-		  LC_ALL=C $(AWK) \
-		    -v dataform='$(DATAFORM)' \
-		    -v deps='$(DSTDATA_ZI_DEPS) zishrink.awk' \
-		    -v redo='$(REDO)' \
-		    -v version="$$version" \
-		    -f zishrink.awk \
-		    $(DATAFORM).zi >$@.out
-		mv $@.out $@
-
-version.h:	version
-		VERSION=`cat version` && printf '%s\n' \
-		  'static char const PKGVERSION[]="($(PACKAGE)) ";' \
-		  "static char const TZVERSION[]=\"$$VERSION\";" \
-		  'static char const REPORT_BUGS_TO[]="$(BUGEMAIL)";' \
-		  >$@.out
-		mv $@.out $@
-
-zdump:		$(TZDOBJS)
-		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS)
-
-zic:		$(TZCOBJS)
-		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS)
-
-leapseconds:	$(LEAP_DEPS)
-		$(AWK) -v EXPIRES_LINE=$(EXPIRES_LINE) \
-		  -f leapseconds.awk leap-seconds.list >$@.out
-		mv $@.out $@
-
-# Arguments to pass to submakes of install_data.
-# They can be overridden by later submake arguments.
-INSTALLARGS = \
- BACKWARD='$(BACKWARD)' \
- DESTDIR='$(DESTDIR)' \
- LEAPSECONDS='$(LEAPSECONDS)' \
- PACKRATDATA='$(PACKRATDATA)' \
- TZDEFAULT='$(TZDEFAULT)' \
- TZDIR='$(TZDIR)' \
- ZIC='$(ZIC)'
-
-INSTALL_DATA_DEPS = zic leapseconds tzdata.zi
-
-# 'make install_data' installs one set of TZif files.
-install_data: $(INSTALL_DATA_DEPS)
-		$(ZIC_INSTALL) tzdata.zi
-
-posix_only: $(INSTALL_DATA_DEPS)
-		$(MAKE) $(INSTALLARGS) LEAPSECONDS= install_data
-
-right_only: $(INSTALL_DATA_DEPS)
-		$(MAKE) $(INSTALLARGS) LEAPSECONDS='-L leapseconds' \
-			install_data
-
-# In earlier versions of this makefile, the other two directories were
-# subdirectories of $(TZDIR).  However, this led to configuration errors.
-# For example, with posix_right under the earlier scheme,
-# TZ='right/Australia/Adelaide' got you localtime with leap seconds,
-# but gmtime without leap seconds, which led to problems with applications
-# like sendmail that subtract gmtime from localtime.
-# Therefore, the other two directories are now siblings of $(TZDIR).
-# You must replace all of $(TZDIR) to switch from not using leap seconds
-# to using them, or vice versa.
-right_posix:	right_only
-		rm -fr '$(DESTDIR)$(TZDIR)-leaps'
-		ln -s '$(TZDIR_BASENAME)' '$(DESTDIR)$(TZDIR)-leaps' || \
-		  $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-leaps' right_only
-		$(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-posix' posix_only
-
-posix_right:	posix_only
-		rm -fr '$(DESTDIR)$(TZDIR)-posix'
-		ln -s '$(TZDIR_BASENAME)' '$(DESTDIR)$(TZDIR)-posix' || \
-		  $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-posix' posix_only
-		$(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-leaps' right_only
-
-# This obsolescent rule is present for backwards compatibility with
-# tz releases 2014g through 2015g.  It should go away eventually.
-posix_packrat: $(INSTALL_DATA_DEPS)
-		$(MAKE) $(INSTALLARGS) PACKRATDATA=backzone posix_only
-
-zones:		$(REDO)
-
-# dummy.zd is not a real file; it is mentioned here only so that the
-# top-level 'make' does not have a syntax error.
-ZDS = dummy.zd
-# Rule used only by submakes invoked by the $(TZS_NEW) rule.
-# It is separate so that GNU 'make -j' can run instances in parallel.
-$(ZDS): zdump
-		./zdump -i $(TZS_CUTOFF_FLAG) '$(wd)/'$$(expr $@ : '\(.*\).zd') \
-		  >$@
-
-TZS_NEW_DEPS = tzdata.zi zdump zic
-$(TZS_NEW): $(TZS_NEW_DEPS)
-		rm -fr tzs$(TZS_YEAR).dir
-		mkdir tzs$(TZS_YEAR).dir
-		$(zic) -d tzs$(TZS_YEAR).dir tzdata.zi
-		$(AWK) '/^L/{print "Link\t" $$2 "\t" $$3}' \
-		   tzdata.zi | LC_ALL=C sort >$@.out
-		wd=`pwd` && \
-		x=`$(AWK) '/^Z/{print "tzs$(TZS_YEAR).dir/" $$2 ".zd"}' \
-				tzdata.zi \
-			| LC_ALL=C sort -t . -k 2,2` && \
-		set x $$x && \
-		shift && \
-		ZDS=$$* && \
-		$(MAKE) wd="$$wd" TZS_CUTOFF_FLAG="$(TZS_CUTOFF_FLAG)" \
-		  ZDS="$$ZDS" $$ZDS && \
-		sed 's,^TZ=".*\.dir/,TZ=",' $$ZDS >>$@.out
-		rm -fr tzs$(TZS_YEAR).dir
-		mv $@.out $@
-
-# If $(TZS) exists but 'make check_tzs' fails, a maintainer should inspect the
-# failed output and fix the inconsistency, perhaps by running 'make force_tzs'.
-$(TZS):
-		touch $@
-
-force_tzs:	$(TZS_NEW)
-		cp $(TZS_NEW) $(TZS)
-
-libtz.a:	$(LIBOBJS)
-		rm -f $@
-		$(AR) -rc $@ $(LIBOBJS)
-		$(RANLIB) $@
-
-date:		$(DATEOBJS)
-		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(DATEOBJS) $(LDLIBS)
-
-tzselect:	tzselect.ksh version
-		VERSION=`cat version` && sed \
-			-e 's|#!/bin/bash|#!$(KSHELL)|g' \
-			-e 's|AWK=[^}]*|AWK='\''$(AWK)'\''|g' \
-			-e 's|\(PKGVERSION\)=.*|\1='\''($(PACKAGE)) '\''|' \
-			-e 's|\(REPORT_BUGS_TO\)=.*|\1=$(BUGEMAIL)|' \
-			-e 's|TZDIR=[^}]*|TZDIR=$(TZDIR)|' \
-			-e 's|\(TZVERSION\)=.*|\1='"$$VERSION"'|' \
-			<$@.ksh >$@.out
-		chmod +x $@.out
-		mv $@.out $@
-
-check:		check_character_set check_white_space check_links \
-		  check_name_lengths check_sorted \
-		  check_tables check_web check_zishrink check_tzs
-
-check_character_set: $(ENCHILADA)
-	test ! '$(UTF8_LOCALE)' || \
-	! printf 'A\304\200B\n' | \
-	  LC_ALL='$(UTF8_LOCALE)' grep -q '^A.B$$' >/dev/null 2>&1 || { \
-		LC_ALL='$(UTF8_LOCALE)' && export LC_ALL && \
-		sharp='#' && \
-		! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \
-			$(MISC) $(SOURCES) $(WEB_PAGES) \
-			CONTRIBUTING LICENSE README SECURITY \
-			version tzdata.zi && \
-		! grep -Env $(SAFE_LINE)'|^UNUSUAL_OK_'$(OK_CHAR)'*$$' \
-			Makefile && \
-		! grep -Env $(SAFE_SHARP_LINE) $(TDATA_TO_CHECK) backzone \
-			leapseconds zone.tab && \
-		! grep -Env $(OK_LINE) $(ENCHILADA); \
-	}
+MAKE=make
+SHELL=/bin/bash
+PYTHON24=python2.4
+PYTHON25=python2.5
+PYTHON26=python2.6
+PYTHON27=python2.7
+PYTHON31=python3.1
+PYTHON32=python3.2
+PYTHON33=python3.3
+PYTHON34=python3.4
+PYTHON35=python3.5
+PYTHON36=python3.6
+PYTHON37=python3.7
+PYTHON38=python3.8
+PYTHON39=python3.9
+PYTHON310=python3.10
+PYTHON2=/usr/bin/python2
+PYTHON3=/usr/bin/python3
+PYTHON=${PYTHON3}
+IANA=./tz
+IANA_GIT=https://github.com/eggert/tz.git
+
+TESTARGS=-vv
+TARGET=
+#TARGET=Europe/Amsterdam Europe/Moscow W-SU Etc/GMT+2 Atlantic/South_Georgia Europe/Warsaw Europe/Vilnius
+#Mideast/Riyadh87
+STYLESHEET=/usr/share/python-docutils/stylesheets/default.css
+
+all: dist
+
+check: test_tzinfo test_docs
+
+build: .stamp-tzinfo
+
+
+dist: build wheels
+	cd build/dist && mkdir -p ../tarballs && \
+	${PYTHON} setup.py -q sdist --dist-dir ../tarballs \
+	    --formats=bztar,gztar,zip
+
+wheels:
+	cd build/dist && mkdir -p ../tarballs
+	cd build/dist && ${PYTHON} setup.py -q bdist_wheel --universal --dist-dir=../tarballs
+	cd build/dist && ${PYTHON3} setup.py -q bdist_wheel --universal --dist-dir=../tarballs
+
+upload: sign
+	cd build/dist && ${PYTHON3} setup.py register
+	twine upload build/tarballs/*.{whl,gz,asc}
+
+sign:
+	rm -f build/tarballs/*.asc
+	for f in build/tarballs/*.{whl,zip,bz2,gz} ; do \
+	    gpg --detach-sign -a $$f; \
+	done
+
+test: test_lazy test_tzinfo test_docs test_zdump
+
+lint: .stamp-tzinfo
+	flake8 --ignore=E402 build/dist gen_*.py test_zdump.py
+
+clean:
+	rm -f .stamp-*
+	rm -rf build/*/* zdump.out
+	make -C ${IANA} clean
+	find . -name \*.pyc | xargs rm -f
+
+test_lazy: .stamp-tzinfo
+	cd build/dist/pytz/tests \
+	    && ${PYTHON24} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON25} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON26} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON27} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON31} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON32} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON33} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON34} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON35} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON36} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON37} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON38} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON39} test_lazy.py ${TESTARGS} \
+	    && ${PYTHON310} test_lazy.py ${TESTARGS}
+
+test_tzinfo: .stamp-tzinfo
+	cd build/dist/pytz/tests \
+	    && ${PYTHON24} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON25} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON26} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON27} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON31} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON32} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON33} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON34} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON35} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON36} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON37} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON38} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON39} test_tzinfo.py ${TESTARGS} \
+	    && ${PYTHON310} test_tzinfo.py ${TESTARGS}
+
+test_docs: .stamp-tzinfo
+	cd build/dist/pytz/tests \
+	    && ${PYTHON3} test_docs.py ${TESTARGS} \
+	    && ${PYTHON2} test_docs.py ${TESTARGS}
+
+test_zdump: dist
+	${PYTHON3} gen_tests.py ${TARGET} && \
+	${PYTHON3} test_zdump.py ${TESTARGS} && \
+	${PYTHON2} test_zdump.py ${TESTARGS} && \
+	${PYTHON310} test_zdump.py ${TESTARGS}
+
+build/dist/test_zdump.py: .stamp-zoneinfo
+
+doc: docs
+
+docs: dist
+	mkdir -p build/docs/source/.static
+	mkdir -p build/docs/built
+	cp src/README.rst build/docs/source/index.txt
+	cp conf.py build/docs/source/conf.py
+	sphinx-build build/docs/source build/docs/built
+	chmod -R og-w build/docs/built
+	chmod -R a+rX build/docs/built
+
+upload_docs: upload_docs_pythonhosted upload_docs_sf
+
+upload_docs_sf: docs
+	rsync -e ssh -ravP build/docs/built/ \
+	    web.sourceforge.net:/home/project-web/pytz/htdocs/
+
+upload_docs_pythonhosted: docs
+	cd build/dist \
+	    && ${PYTHON} setup.py upload_docs --upload-dir=../docs/built
+
+.stamp-tzinfo: .stamp-zoneinfo gen_tzinfo.py build/etc/zoneinfo/GMT
+	${PYTHON} gen_tzinfo.py ${TARGET}
+	rm -rf build/dist/pytz/zoneinfo
+	cp -a build/etc/zoneinfo build/dist/pytz/zoneinfo
 	touch $@
 
-check_white_space: $(ENCHILADA)
-		patfmt=' \t|[\f\r\v]' && pat=`printf "$$patfmt\\n"` && \
-		! grep -En "$$pat" \
-			$$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list)
-		! grep -n '[[:space:]]$$' \
-			$$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list)
-		touch $@
-
-PRECEDES_FILE_NAME = ^(Zone|Link[[:space:]]+[^[:space:]]+)[[:space:]]+
-FILE_NAME_COMPONENT_TOO_LONG = \
-  $(PRECEDES_FILE_NAME)[^[:space:]]*[^/[:space:]]{15}
-
-check_name_lengths: $(TDATA_TO_CHECK) backzone
-		! grep -En '$(FILE_NAME_COMPONENT_TOO_LONG)' \
-			$(TDATA_TO_CHECK) backzone
-		touch $@
-
-CHECK_CC_LIST = { n = split($$1,a,/,/); for (i=2; i<=n; i++) print a[1], a[i]; }
-
-check_sorted: backward backzone iso3166.tab zone.tab zone1970.tab
-		$(AWK) '/^Link/ {print $$3}' backward | LC_ALL=C sort -cu
-		$(AWK) '/^Zone/ {print $$2}' backzone | LC_ALL=C sort -cu
-		touch $@
-
-check_links:	checklinks.awk $(TDATA_TO_CHECK) tzdata.zi
-		$(AWK) -f checklinks.awk $(TDATA_TO_CHECK)
-		$(AWK) -f checklinks.awk tzdata.zi
-		touch $@
-
-check_tables:	checktab.awk $(YDATA) backward $(ZONETABLES)
-		for tab in $(ZONETABLES); do \
-		  test "$$tab" = zone.tab && links='$(BACKWARD)' || links=''; \
-		  $(AWK) -f checktab.awk -v zone_table=$$tab $(YDATA) $$links \
-		    || exit; \
-		done
-		touch $@
-
-check_tzs:	$(TZS) $(TZS_NEW)
-		if test -s $(TZS); then \
-		  diff -u $(TZS) $(TZS_NEW); \
-		else \
-		  cp $(TZS_NEW) $(TZS); \
-		fi
-		touch $@
-
-check_web:	$(CHECK_WEB_PAGES)
-check_theory.html: theory.html
-check_tz-art.html: tz-art.html
-check_tz-how-to.html: tz-how-to.html
-check_tz-link.html: tz-link.html
-check_theory.html check_tz-art.html check_tz-how-to.html check_tz-link.html:
-		$(CURL) -sS --url https://validator.w3.org/nu/ -F out=gnu \
-		    -F file=@$$(expr $@ : 'check_\(.*\)') -o $@.out && \
-		  test ! -s $@.out || { cat $@.out; exit 1; }
-		mv $@.out $@
-
-# Check that zishrink.awk does not alter the data, and that ziguard.awk
-# preserves main-format data.
-check_zishrink: check_zishrink_posix check_zishrink_right
-check_zishrink_posix check_zishrink_right: \
-  zic leapseconds $(PACKRATDATA) $(TDATA) $(DATAFORM).zi tzdata.zi
-		rm -fr $@.dir $@-t.dir $@-shrunk.dir
-		mkdir $@.dir $@-t.dir $@-shrunk.dir
-		case $@ in \
-		  *_right) leap='-L leapseconds';; \
-		  *) leap=;; \
-		esac && \
-		  $(ZIC) $$leap -d $@.dir $(DATAFORM).zi && \
-		  $(ZIC) $$leap -d $@-shrunk.dir tzdata.zi && \
-		  case $(DATAFORM) in \
-		    main) \
-		      $(ZIC) $$leap -d $@-t.dir $(TDATA) && \
-		      $(AWK) '/^Rule/' $(TDATA) | \
-			$(ZIC) $$leap -d $@-t.dir - $(PACKRATDATA) && \
-		      diff -r $@.dir $@-t.dir;; \
-		  esac
-		diff -r $@.dir $@-shrunk.dir
-		rm -fr $@.dir $@-t.dir $@-shrunk.dir
-		touch $@
-
-clean_misc:
-		rm -fr check_*.dir
-		rm -f *.o *.out $(TIME_T_ALTERNATIVES) \
-		  check_* core typecheck_* \
-		  date tzselect version.h zdump zic libtz.a
-clean:		clean_misc
-		rm -fr *.dir tzdb-*/
-		rm -f *.zi $(TZS_NEW)
-
-maintainer-clean: clean
-		@echo 'This command is intended for maintainers to use; it'
-		@echo 'deletes files that may need special tools to rebuild.'
-		rm -f leapseconds version $(MANTXTS) $(TZS) *.asc *.tar.*
-
-names:
-		@echo $(ENCHILADA)
-
-public:		check check_public $(CHECK_TIME_T_ALTERNATIVES) \
-		tarballs signatures
+.stamp-zoneinfo:
+	${MAKE} -C ${IANA} ZFLAGS='-b fat' TOPDIR=`pwd`/build USRDIR= USRSHAREDIR=etc install
+	# Break hard links, working around http://bugs.python.org/issue8876.
+	for d in zoneinfo zoneinfo-leaps zoneinfo-posix; do \
+	    rm -rf `pwd`/build/etc/$$d.tmp; \
+	    rsync -a `pwd`/build/etc/$$d/ `pwd`/build/etc/$$d.tmp; \
+	    rm -rf `pwd`/build/etc/$$d; \
+	    mv `pwd`/build/etc/$$d.tmp `pwd`/build/etc/$$d; \
+	done
+	touch $@
 
-date.1.txt:	date.1
-newctime.3.txt:	newctime.3
-newstrftime.3.txt: newstrftime.3
-newtzset.3.txt:	newtzset.3
-time2posix.3.txt: time2posix.3
-tzfile.5.txt:	tzfile.5
-tzselect.8.txt:	tzselect.8
-zdump.8.txt:	zdump.8
-zic.8.txt:	zic.8
+build/dist/locales/pytz.pot: .stamp-tzinfo
+	@: #${PYTHON} gen_pot.py build/dist/pytz/locales/pytz.pot
 
-$(MANTXTS):	workman.sh
-		LC_ALL=C sh workman.sh `expr $@ : '\(.*\)\.txt$$'` >$@.out
-		mv $@.out $@
+#	cd build/dist; mkdir locales; \
+#	pygettext --extract-all --no-location \
+#	    --default-domain=pytz --output-dir=locales
 
-# Set file timestamps deterministically if possible,
-# so that tarballs containing the timestamps are reproducible.
+# Switch to using a git subtree of https://github.com/eggert/tz
 #
-# '$(SET_TIMESTAMP_N) N DEST A B C ...' sets the timestamp of the
-# file DEST to the maximum of the timestamps of the files A B C ...,
-# plus N if GNU ls and touch are available.
-SET_TIMESTAMP_N = sh -c '\
-  n=$$0 dest=$$1; shift; \
-  touch -cmr `ls -t "$$@" | sed 1q` "$$dest" && \
-  if test $$n != 0 && \
-     lsout=`ls -n --time-style="+%s" "$$dest" 2>/dev/null`; then \
-    set x $$lsout && \
-    touch -cmd @`expr $$7 + $$n` "$$dest"; \
-  else :; fi'
-# If DEST depends on A B C ... in this Makefile, callers should use
-# $(SET_TIMESTAMP_DEP) DEST A B C ..., for the benefit of any
-# downstream 'make' that considers equal timestamps to be out of date.
-# POSIX allows this 'make' behavior, and HP-UX 'make' does it.
-# If all that matters is that the timestamp be reproducible
-# and plausible, use $(SET_TIMESTAMP).
-SET_TIMESTAMP = $(SET_TIMESTAMP_N) 0
-SET_TIMESTAMP_DEP = $(SET_TIMESTAMP_N) 1
-
-# Set the timestamps to those of the git repository, if available,
-# and if the files have not changed since then.
-# This uses GNU 'ls --time-style=+%s', which outputs the seconds count,
-# and GNU 'touch -d@N FILE', where N is the number of seconds since 1970.
-# If git or GNU is absent, don't bother to sync with git timestamps.
-# Also, set the timestamp of each prebuilt file like 'leapseconds'
-# to be the maximum of the files it depends on.
-set-timestamps.out: $(EIGHT_YARDS)
-		rm -f $@
-		if (type git) >/dev/null 2>&1 && \
-		   files=`git ls-files $(EIGHT_YARDS)` && \
-		   touch -md @1 test.out; then \
-		  rm -f test.out && \
-		  for file in $$files; do \
-		    if git diff --quiet $$file; then \
-		      time=`git log -1 --format='tformat:%ct' $$file` && \
-		      touch -cmd @$$time $$file; \
-		    else \
-		      echo >&2 "$$file: warning: does not match repository"; \
-		    fi || exit; \
-		  done; \
-		fi
-		$(SET_TIMESTAMP_DEP) leapseconds $(LEAP_DEPS)
-		for file in `ls $(MANTXTS) | sed 's/\.txt$$//'`; do \
-		  $(SET_TIMESTAMP_DEP) $$file.txt $$file workman.sh || \
-		    exit; \
-		done
-		$(SET_TIMESTAMP_DEP) version $(VERSION_DEPS)
-		$(SET_TIMESTAMP_DEP) tzdata.zi $(TZDATA_ZI_DEPS)
-		touch $@
-set-tzs-timestamp.out: $(TZS)
-		$(SET_TIMESTAMP_DEP) $(TZS) $(TZS_DEPS)
-		touch $@
-
-# The zics below ensure that each data file can stand on its own.
-# We also do an all-files run to catch links to links.
-
-check_public: $(VERSION_DEPS)
-		rm -fr public.dir
-		mkdir public.dir
-		ln $(VERSION_DEPS) public.dir
-		cd public.dir && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' ALL
-		for i in $(TDATA_TO_CHECK) public.dir/tzdata.zi \
-		    public.dir/vanguard.zi public.dir/main.zi \
-		    public.dir/rearguard.zi; \
-		do \
-		  public.dir/zic -v -d public.dir/zoneinfo $$i 2>&1 || exit; \
-		done
-		public.dir/zic -v -d public.dir/zoneinfo-all $(TDATA_TO_CHECK)
-		:
-		: Also check 'backzone' syntax.
-		rm public.dir/main.zi
-		cd public.dir && $(MAKE) PACKRATDATA=backzone main.zi
-		public.dir/zic -d public.dir/zoneinfo main.zi
-		:
-		rm -fr public.dir
-		touch $@
-
-# Check that the code works under various alternative
-# implementations of time_t.
-check_time_t_alternatives: $(TIME_T_ALTERNATIVES)
-$(TIME_T_ALTERNATIVES_TAIL): $(TIME_T_ALTERNATIVES_HEAD)
-$(TIME_T_ALTERNATIVES): $(VERSION_DEPS)
-		rm -fr $@.dir
-		mkdir $@.dir
-		ln $(VERSION_DEPS) $@.dir
-		case $@ in \
-		  int*32_t) range=-2147483648,2147483648;; \
-		  u*) range=0,4294967296;; \
-		  *) range=-4294967296,4294967296;; \
-		esac && \
-		wd=`pwd` && \
-		zones=`$(AWK) '/^[^#]/ { print $$3 }' <zone1970.tab` && \
-		if test $@ = $(TIME_T_ALTERNATIVES_HEAD); then \
-		  range_target=; \
-		else \
-		  range_target=to$$range.tzs; \
-		fi && \
-		(cd $@.dir && \
-		  $(MAKE) TOPDIR="$$wd/$@.dir" \
-		    CFLAGS='$(CFLAGS) -Dtime_tz='"'$@'" \
-		    REDO='$(REDO)' \
-			D=$$wd/$@.dir \
-		    TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \
-		    install $$range_target) && \
-		test $@ = $(TIME_T_ALTERNATIVES_HEAD) || { \
-		  (cd $(TIME_T_ALTERNATIVES_HEAD).dir && \
-		    $(MAKE) TOPDIR="$$wd/$@.dir" \
-		      TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \
-			D=$$wd/$@.dir \
-		      to$$range.tzs) && \
-		  diff -u $(TIME_T_ALTERNATIVES_HEAD).dir/to$$range.tzs \
-			  $@.dir/to$$range.tzs && \
-		  if diff -q Makefile Makefile 2>/dev/null; then \
-		    quiet_option='-q'; \
-		  else \
-		    quiet_option=''; \
-		  fi && \
-		    diff $$quiet_option -r $(TIME_T_ALTERNATIVES_HEAD).dir/etc \
-					   $@.dir/etc && \
-		    diff $$quiet_option -r \
-		      $(TIME_T_ALTERNATIVES_HEAD).dir/usr/share \
-		      $@.dir/usr/share; \
-		}
-		touch $@
-
-TRADITIONAL_ASC = \
-  tzcode$(VERSION).tar.gz.asc \
-  tzdata$(VERSION).tar.gz.asc
-REARGUARD_ASC = \
-  tzdata$(VERSION)-rearguard.tar.gz.asc
-ALL_ASC = $(TRADITIONAL_ASC) $(REARGUARD_ASC) \
-  tzdb-$(VERSION).tar.lz.asc
-
-tarballs rearguard_tarballs traditional_tarballs \
-signatures rearguard_signatures traditional_signatures: \
-  version set-timestamps.out rearguard.zi
-		VERSION=`cat version` && \
-		$(MAKE) AWK='$(AWK)' VERSION="$$VERSION" $@_version
-
-# These *_version rules are intended for use if VERSION is set by some
-# other means.  Ordinarily these rules are used only by the above
-# non-_version rules, which set VERSION on the 'make' command line.
-tarballs_version: traditional_tarballs_version rearguard_tarballs_version \
-  tzdb-$(VERSION).tar.lz
-rearguard_tarballs_version: \
-  tzdata$(VERSION)-rearguard.tar.gz
-traditional_tarballs_version: \
-  tzcode$(VERSION).tar.gz tzdata$(VERSION).tar.gz
-signatures_version: $(ALL_ASC)
-rearguard_signatures_version: $(REARGUARD_ASC)
-traditional_signatures_version: $(TRADITIONAL_ASC)
-
-tzcode$(VERSION).tar.gz: set-timestamps.out
-		LC_ALL=C && export LC_ALL && \
-		tar $(TARFLAGS) -cf - \
-		    $(COMMON) $(DOCS) $(SOURCES) | \
-		  gzip $(GZIPFLAGS) >$@.out
-		mv $@.out $@
-
-tzdata$(VERSION).tar.gz: set-timestamps.out
-		LC_ALL=C && export LC_ALL && \
-		tar $(TARFLAGS) -cf - $(COMMON) $(DATA) $(MISC) | \
-		  gzip $(GZIPFLAGS) >$@.out
-		mv $@.out $@
-
-tzdata$(VERSION)-rearguard.tar.gz: rearguard.zi set-timestamps.out
-		rm -fr tzdata$(VERSION)-rearguard.dir
-		mkdir tzdata$(VERSION)-rearguard.dir
-		ln $(COMMON) $(DATA) $(MISC) tzdata$(VERSION)-rearguard.dir
-		cd tzdata$(VERSION)-rearguard.dir && \
-		  rm -f $(TDATA) $(PACKRATDATA) version
-		for f in $(TDATA) $(PACKRATDATA); do \
-		  rearf=tzdata$(VERSION)-rearguard.dir/$$f; \
-		  $(AWK) -v DATAFORM=rearguard -f ziguard.awk $$f >$$rearf && \
-		  $(SET_TIMESTAMP_DEP) $$rearf ziguard.awk $$f || exit; \
-		done
-		sed '1s/$$/-rearguard/' \
-		  <version >tzdata$(VERSION)-rearguard.dir/version
-		: The dummy pacificnew pacifies TZUpdater 2.3.1 and earlier.
-		TZ=UTC0 touch -mt 202010122253.00 \
-		  tzdata$(VERSION)-rearguard.dir/pacificnew
-		touch -cmr version tzdata$(VERSION)-rearguard.dir/version
-		LC_ALL=C && export LC_ALL && \
-		  (cd tzdata$(VERSION)-rearguard.dir && \
-		   tar $(TARFLAGS) -cf - \
-			$(COMMON) $(DATA) $(MISC) pacificnew | \
-		     gzip $(GZIPFLAGS)) >$@.out
-		mv $@.out $@
-
-tzdb-$(VERSION).tar.lz: set-timestamps.out set-tzs-timestamp.out
-		rm -fr tzdb-$(VERSION)
-		mkdir tzdb-$(VERSION)
-		ln $(ENCHILADA) tzdb-$(VERSION)
-		$(SET_TIMESTAMP) tzdb-$(VERSION) tzdb-$(VERSION)/*
-		LC_ALL=C && export LC_ALL && \
-		tar $(TARFLAGS) -cf - tzdb-$(VERSION) | lzip -9 >$@.out
-		mv $@.out $@
-
-tzcode$(VERSION).tar.gz.asc: tzcode$(VERSION).tar.gz
-tzdata$(VERSION).tar.gz.asc: tzdata$(VERSION).tar.gz
-tzdata$(VERSION)-rearguard.tar.gz.asc: tzdata$(VERSION)-rearguard.tar.gz
-tzdb-$(VERSION).tar.lz.asc: tzdb-$(VERSION).tar.lz
-$(ALL_ASC):
-		$(GPG) --armor --detach-sign $?
-
-TYPECHECK_CFLAGS = $(CFLAGS) -DTYPECHECK -D__time_t_defined -D_TIME_T
-typecheck: typecheck_long_long typecheck_unsigned
-typecheck_long_long typecheck_unsigned: $(VERSION_DEPS)
-		rm -fr $@.dir
-		mkdir $@.dir
-		ln $(VERSION_DEPS) $@.dir
-		cd $@.dir && \
-		  case $@ in \
-		    *_long_long) i="long long";; \
-		    *_unsigned ) i="unsigned" ;; \
-		  esac && \
-		  typecheck_cflags='' && \
-		  $(MAKE) \
-		    CFLAGS="$(TYPECHECK_CFLAGS) \"-Dtime_t=$$i\"" \
-		    TOPDIR="`pwd`" \
-		    install
-		$@.dir/zdump -i -c 1970,1971 Europe/Rome
-		touch $@
-
-zonenames:	tzdata.zi
-		@$(AWK) '/^Z/ { print $$2 } /^L/ { print $$3 }' tzdata.zi
-
-asctime.o:	private.h tzfile.h
-date.o:		private.h
-difftime.o:	private.h
-localtime.o:	private.h tzfile.h
-strftime.o:	private.h tzfile.h
-zdump.o:	version.h
-zic.o:		private.h tzfile.h version.h
-
-.PHONY: ALL INSTALL all
-.PHONY: check check_time_t_alternatives
-.PHONY: check_web check_zishrink
-.PHONY: clean clean_misc dummy.zd force_tzs
-.PHONY: install install_data maintainer-clean names
-.PHONY: posix_only posix_packrat posix_right public
-.PHONY: rearguard_signatures rearguard_signatures_version
-.PHONY: rearguard_tarballs rearguard_tarballs_version
-.PHONY: right_only right_posix signatures signatures_version
-.PHONY: tarballs tarballs_version
-.PHONY: traditional_signatures traditional_signatures_version
-.PHONY: traditional_tarballs traditional_tarballs_version
-.PHONY: typecheck
-.PHONY: zonenames zones
-.PHONY: $(ZDS)
+# IANA_URL=http://www.iana.org/time-zones/repository
+# 
+# sync:
+# 	cd elsie.nci.nih.gov && \
+# 	    rm -f tz{code,data}-latest.tar.gz{,.asc} && \
+# 	    wget -S ${IANA_URL}/tzcode-latest.tar.gz && \
+# 	    wget -S ${IANA_URL}/tzcode-latest.tar.gz.asc && \
+# 	    gpg --verify tzcode-latest.tar.gz.asc tzcode-latest.tar.gz && \
+# 	    wget -S ${IANA_URL}/tzdata-latest.tar.gz && \
+# 	    wget -S ${IANA_URL}/tzdata-latest.tar.gz.asc && \
+# 	    gpg --verify tzdata-latest.tar.gz.asc tzdata-latest.tar.gz && \
+# 	    cd src && \
+# 	    tar xzf ../tzcode-latest.tar.gz && \
+# 	    tar xzf ../tzdata-latest.tar.gz && \
+# 	    echo Done
+
+sync: _sync clean
+
+_sync:
+	if [ -n "$(TAG)" ]; then \
+	    git subtree pull --prefix=tz --squash $(IANA_GIT) $(TAG) \
+		-m "IANA $(TAG)"; \
+	else \
+	    echo "Usage: make sync TAG=2016f"; \
+	fi
+
+.PHONY: all check dist test test_tzinfo test_docs test_zdump wheels build clean sync _sync
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..1f09ee3
--- /dev/null
+++ b/README.md
@@ -0,0 +1,27 @@
+# pytz
+
+Brings the IANA tz database into Python. This library allows accurate and
+cross platform timezone calculations.
+
+pytz contains generated code, and this branch generates it. The actual
+pytz code and documentation can be found in the src/ directory.
+
+## Usage Information / Documentation
+
+See [the pytz README](src/README.rst).
+
+## pytz for Enterprise
+
+Available as part of the Tidelift Subscription.
+
+The maintainers of pytz and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. [Learn more.](https://tidelift.com/subscription/pkg/pypi-pytz?utm_source=pypi-pytz&utm_medium=referral&utm_campaign=enterprise&utm_term=repo)
+
+
+## Release process ##
+
+    1) Untar upstream tarballs into elsie/src
+    2) Update VERSION & OLSON_VERSION in src/pytz/__init__.py, and EXPECTED_VERSION in
+       src/pytz/tests/test_tzinfo.py
+    3) make test
+    4) make dist
+
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000..707e927
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,4 @@
+# Security Reports
+
+Security reports can be made via [Tidelift](https://tidelift.com/security).
+Tidelift will coordinate the fix and disclosure.
diff --git a/conf.py b/conf.py
new file mode 100644
index 0000000..036b07e
--- /dev/null
+++ b/conf.py
@@ -0,0 +1,182 @@
+# -*- coding: utf-8 -*-
+#
+# pytz documentation build configuration file, created by
+# sphinx-quickstart on Sat Oct 11 19:39:58 2008.
+#
+# This file is execfile()d with the current directory set to its containing dir.
+#
+# The contents of this file are pickled, so don't put values in the namespace
+# that aren't pickleable (module imports are okay, they're removed automatically).
+#
+# All configuration values have a default value; values that are commented out
+# serve to show the default value.
+
+import sys, os.path
+sys.path.insert(0, os.path.join(
+    os.path.dirname(__file__), os.pardir, os.pardir, 'dist'))
+import pytz
+
+# If your extensions are in another directory, add it here. If the directory
+# is relative to the documentation root, use os.path.abspath to make it
+# absolute, like shown here.
+#sys.path.append(os.path.abspath('some/directory'))
+
+# General configuration
+# ---------------------
+
+# Add any Sphinx extension module names here, as strings. They can be extensions
+# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
+extensions = []
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['.templates']
+
+# The suffix of source filenames.
+source_suffix = '.txt'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General substitutions.
+project = u'pytz'
+copyright = u'2008, Stuart Bishop'
+
+# The default replacements for |version| and |release|, also used in various
+# other places throughout the built documents.
+#
+# The short X.Y version.
+version = pytz.__version__
+# The full version, including alpha/beta/rc tags.
+release = pytz.__version__
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#today = ''
+# Else, today_fmt is used as the format for a strftime call.
+today_fmt = '%B %d, %Y'
+
+# List of documents that shouldn't be included in the build.
+#unused_docs = []
+
+# List of directories, relative to source directories, that shouldn't be searched
+# for source files.
+exclude_trees = ['.build']
+
+# The reST default role (used for this markup: `text`) to use for all documents.
+#default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+#show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+
+# Options for HTML output
+# -----------------------
+
+# The style sheet to use for HTML and HTML Help pages. A file of that name
+# must exist either in Sphinx' static/ path, or in one of the custom paths
+# given in html_static_path.
+html_style = 'default.css'
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+#html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['.static']
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+#html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#html_additional_pages = {}
+
+# If false, no module index is generated.
+html_use_modindex = False
+
+# If false, no index is generated.
+html_use_index = False
+
+# If true, the index is split into individual pages for each letter.
+#html_split_index = False
+
+# If true, the reST sources are included in the HTML build as _sources/<name>.
+#html_copy_source = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#html_use_opensearch = ''
+
+# If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
+html_file_suffix = '.html'
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'pytzdoc'
+
+
+# Options for LaTeX output
+# ------------------------
+
+# The paper size ('letter' or 'a4').
+#latex_paper_size = 'letter'
+
+# The font size ('10pt', '11pt' or '12pt').
+#latex_font_size = '10pt'
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title, author, document class [howto/manual]).
+latex_documents = [
+  ('index', 'pytz.tex', u'pytz Documentation',
+   u'Stuart Bishop', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+#latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+#latex_use_parts = False
+
+# Additional stuff for the LaTeX preamble.
+#latex_preamble = ''
+
+# Documents to append as an appendix to all manuals.
+#latex_appendices = []
+
+# If false, no module index is generated.
+#latex_use_modindex = True
diff --git a/deps.rst b/deps.rst
new file mode 100644
index 0000000..80688dd
--- /dev/null
+++ b/deps.rst
@@ -0,0 +1,19 @@
+dev container setup cheat sheet
+-------------------------------
+
+.. code::
+
+    locale-gen
+    add-apt-repository ppa:deadsnakes/ppa
+
+    apt update
+    apt install tox bzr build-essential twine python-all python-all-dev python3-all python3-all-dev python3-docutils python3-sphinx python3-flake8 python-flake8 python2.4-complete python2.5-complete python2.6-complete python3.1-complete python3.2-complete python3.3-complete python3.4-complete python3.5 python3.5-dev python3.7 python3.7-dev  python-wheel python3-wheel python-pip python3-pip
+
+
+    wget https://raw.githubusercontent.com/pypa/setuptools/bootstrap-py24/ez_setup.py -O - | python2.4
+    wget https://raw.githubusercontent.com/pypa/setuptools/bootstrap-py24/ez_setup.py -O - | python2.5
+    wget https://bootstrap.pypa.io/ez_setup.py -O - | python2.6
+    wget https://bootstrap.pypa.io/ez_setup.py -O - | python3.1
+    wget https://bootstrap.pypa.io/ez_setup.py -O - | python3.2
+    wget https://bootstrap.pypa.io/ez_setup.py -O - | python3.3
+    wget https://bootstrap.pypa.io/ez_setup.py -O - | python3.4
diff --git a/gen_pot.py b/gen_pot.py
new file mode 100644
index 0000000..79c4e9d
--- /dev/null
+++ b/gen_pot.py
@@ -0,0 +1,39 @@
+from __future__ import print_function
+import sys
+import os.path
+import time
+from gen_tzinfo import allzones
+
+from pytz import __version__
+
+boilerplate = r"""msgid ""
+msgstr ""
+"Project-Id-Version: pytz %s\n"
+"POT-Creation-Date: %s\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+
+""" % (
+    __version__,
+    time.strftime('%Y-%m-%d %H:%M+UTC', time.gmtime(time.time()))
+)
+
+
+def main():
+    assert len(sys.argv) == 2, 'Output file not specified on command line'
+    pot_file_name = sys.argv[1]
+
+    if not os.path.exists(os.path.dirname(pot_file_name)):
+        os.makedirs(os.path.dirname(pot_file_name))
+
+    pot = open(pot_file_name, 'wb')
+
+    print(boilerplate, file=pot)
+
+    for zone in allzones():
+        print('msgid "%s"' % zone, file=pot)
+        print('msgstr ""', file=pot)
+        print(file=pot)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/gen_tests.py b/gen_tests.py
new file mode 100644
index 0000000..ef832fe
--- /dev/null
+++ b/gen_tests.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+# -*- coding: ascii -*-
+'''
+$Id: gen_tests.py,v 1.15 2005/01/07 04:51:30 zenzen Exp $
+'''
+
+import os
+import os.path
+import subprocess
+import sys
+from gen_tzinfo import allzones
+import gen_tzinfo
+
+zdump = os.path.abspath(os.path.join(
+    os.path.dirname(__file__), 'build', 'bin', 'zdump'
+))
+
+
+def main():
+    dest_dir = os.path.abspath(os.path.join(os.path.dirname(__file__)))
+
+    datf = open(os.path.join(dest_dir, 'zdump.out'), 'w')
+
+    for zone in allzones():
+        print('Collecting zdump(1) output for %s in zdump.out' % (zone,))
+        # We don't yet support v2 format tzfile(5) files, so limit
+        # the daterange we test against - zdump understands v2 format
+        # files and will output historical records we can't cope with
+        # otherwise.
+        command = [zdump, '-V', '-c', '1902,2038', zone]
+        zd_out = subprocess.check_output(command, encoding="utf8")
+        lines = [line.strip() for line in zd_out.splitlines()]
+
+        for line in lines:
+            print(line, file=datf)
+    datf.flush()
+    datf.close()
+
+if __name__ == '__main__':
+    try:
+        gen_tzinfo.target = sys.argv[1:]
+    except IndexError:
+        gen_tzinfo.target = None
+    main()
+
+# vim: set filetype=python ts=4 sw=4 et
diff --git a/gen_tzinfo.py b/gen_tzinfo.py
new file mode 100644
index 0000000..3c372dd
--- /dev/null
+++ b/gen_tzinfo.py
@@ -0,0 +1,155 @@
+#!/usr/bin/env python
+'''
+$Id: gen_tzinfo.py,v 1.21 2005/02/15 20:21:38 zenzen Exp $
+'''
+from __future__ import print_function
+import sys
+import os
+import os.path
+import shutil
+
+from glob import glob
+from pprint import pprint
+import re
+
+zoneinfo = os.path.abspath(os.path.join(
+    os.path.dirname(__file__), 'build', 'etc', 'zoneinfo'
+))
+
+
+def allzones():
+    ''' Return all available tzfile(5) files in the zoneinfo database '''
+    zones = []
+    for dirpath, dirnames, filenames in os.walk(zoneinfo):
+        for f in filenames:
+            p = os.path.join(dirpath, f)
+            if open(p, 'rb').read(4) == b'TZif':
+                zones.append(p)
+    stripnum = len(os.path.commonprefix(zones))
+    zones = [z[stripnum:] for z in zones]
+
+    if target:
+        wanted = target + ['US/Eastern', 'UTC']
+        zones = [z for z in zones if z in wanted]
+    # Does not cope with Riyadh87-89 - it appears this region went
+    # on solar time during this period and their DST offset changed
+    # minute to minute (the Olson database could only capture a precision
+    # of 5 seconds because of way too many zone changes, so the data isn't
+    # 100% accurate anyway).
+    # 'Factory' and 'localtime' appear to be Olson reference code specific
+    # and are skipped
+    zones = [z for z in zones if 'Riyadh8' not in z and z not in [
+        'Factory', 'localtime', 'posixrules']]
+    zones.sort()
+    assert len(zones) > 0
+    return zones
+
+
+def links():
+    '''Mapping of alias -> canonical name'''
+    l = {}
+    olson_src_files = ['tz/vanguard.zi', 'tz/main.zi', 'tz/rearguard.zi']
+    for filename in olson_src_files:
+        for line in open(filename, 'r'):
+            if line.strip().startswith('#') or not line.strip():
+                continue
+            match = re.search(r'^\s*Link\s+([\w/\-]+)\s+([\w/\-]+)', line)
+            if match is not None:
+                new_name = match.group(1)
+                old_name = match.group(2)
+                l[old_name] = new_name
+            else:
+                assert not line.startswith('Link'), line
+    assert 'Portugal' in l, 'Portugal should be in links()'
+    return l
+
+
+def dupe_src(destdir):
+    ''' Copy ./src to our dest directory '''
+    if not os.path.isdir(destdir):
+        os.makedirs(destdir)
+    for f in glob(os.path.join('src', '*')):
+        if not os.path.isdir(f):
+            shutil.copy(f, destdir)
+
+    destdir = os.path.join(destdir, 'pytz')
+    if not os.path.isdir(destdir):
+        os.makedirs(destdir)
+    for f in glob(os.path.join('src', 'pytz', '*')):
+        if not os.path.isdir(f):
+            shutil.copy(f, destdir)
+
+    destdir = os.path.join(destdir, 'tests')
+    if not os.path.isdir(destdir):
+        os.makedirs(destdir)
+    for f in glob(os.path.join('src', 'pytz', 'tests', '*')):
+        if not os.path.isdir(f):
+            shutil.copy(f, destdir)
+
+
+def add_allzones(filename):
+    ''' Append a list of all know timezones to the end of the file '''
+    outf = open(filename, 'a')
+
+    obsolete_zones = links().keys()
+
+    # Calculate 'common' timezones as best we can. We start with all
+    # timezones, strip out the legacy noise, and any name linked to
+    # a more canonical name (eg. Asia/Singapore is preferred to just
+    # Singapore)
+    cz = [
+        z for z in allzones()
+        if (z not in obsolete_zones and
+            '/' in z and
+            not z.startswith('SystemV/') and
+            not z.startswith('Etc/'))]
+    # And extend our list manually with stuff we think deserves to be
+    # labelled 'common'.
+    cz.extend([
+        'UTC', 'GMT', 'US/Eastern', 'US/Pacific', 'US/Mountain',
+        'US/Central', 'US/Arizona', 'US/Hawaii', 'US/Alaska',
+        # Canadian timezones per Bug #506341
+        'Canada/Newfoundland', 'Canada/Atlantic', 'Canada/Eastern',
+        'Canada/Central', 'Canada/Mountain', 'Canada/Pacific'])
+    # And extend out list with all preferred country timezones.
+    zone_tab = open(os.path.join(zoneinfo, 'zone.tab'), 'r')
+    for line in zone_tab:
+        if line.startswith('#'):
+            continue
+        code, coordinates, zone = line.split(None, 4)[:3]
+        if zone not in cz:
+            cz.append(zone)
+    cz.sort()
+
+    print('all_timezones = \\', file=outf)
+    pprint(sorted(allzones()), outf)
+    print('''all_timezones = LazyList(
+        tz for tz in all_timezones if resource_exists(tz))
+        ''', file=outf)
+    print('all_timezones_set = LazySet(all_timezones)', file=outf)
+    # Per lp:1835784 we can't afford to do this at import time
+    # print >> outf, '_all_timezones_lower_to_standard = dict((tz.lower(), tz) for tz in all_timezones)'
+
+    print('common_timezones = \\', file=outf)
+    pprint(cz, outf)
+    print('''common_timezones = LazyList(
+            tz for tz in common_timezones if tz in all_timezones)
+        ''', file=outf)
+    print('common_timezones_set = LazySet(common_timezones)', file=outf)
+
+    outf.close()
+
+
+def main(destdir):
+    _destdir = os.path.join(os.path.abspath(destdir), 'dist')
+
+    dupe_src(_destdir)
+    add_allzones(os.path.join(_destdir, 'pytz', '__init__.py'))
+
+target = None
+if __name__ == '__main__':
+    try:
+        target = sys.argv[1:]
+    except IndexError:
+        target = None
+    main('build')
diff --git a/src/LICENSE.txt b/src/LICENSE.txt
new file mode 100644
index 0000000..5f1c112
--- /dev/null
+++ b/src/LICENSE.txt
@@ -0,0 +1,19 @@
+Copyright (c) 2003-2019 Stuart Bishop <stuart@stuartbishop.net>
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/src/MANIFEST.in b/src/MANIFEST.in
new file mode 100644
index 0000000..fda34e2
--- /dev/null
+++ b/src/MANIFEST.in
@@ -0,0 +1,5 @@
+include *.txt setup.py
+recursive-include pytz *.py
+#recursive-include pytz *.pot
+graft pytz/zoneinfo
+#exclude test_zdump.py
diff --git a/src/README.rst b/src/README.rst
new file mode 100644
index 0000000..1437ead
--- /dev/null
+++ b/src/README.rst
@@ -0,0 +1,596 @@
+pytz - World Timezone Definitions for Python
+============================================
+
+:Author: Stuart Bishop <stuart@stuartbishop.net>
+
+Introduction
+~~~~~~~~~~~~
+
+pytz brings the Olson tz database into Python. This library allows
+accurate and cross platform timezone calculations using Python 2.4
+or higher. It also solves the issue of ambiguous times at the end
+of daylight saving time, which you can read more about in the Python
+Library Reference (``datetime.tzinfo``).
+
+Almost all of the Olson timezones are supported.
+
+.. note::
+
+    This library differs from the documented Python API for
+    tzinfo implementations; if you want to create local wallclock
+    times you need to use the ``localize()`` method documented in this
+    document. In addition, if you perform date arithmetic on local
+    times that cross DST boundaries, the result may be in an incorrect
+    timezone (ie. subtract 1 minute from 2002-10-27 1:00 EST and you get
+    2002-10-27 0:59 EST instead of the correct 2002-10-27 1:59 EDT). A
+    ``normalize()`` method is provided to correct this. Unfortunately these
+    issues cannot be resolved without modifying the Python datetime
+    implementation (see PEP-431).
+
+
+Installation
+~~~~~~~~~~~~
+
+This package can either be installed using ``pip`` or from a tarball using the
+standard Python distutils.
+
+If you are installing using ``pip``, you don't need to download anything as the
+latest version will be downloaded for you from PyPI::
+
+    pip install pytz
+
+If you are installing from a tarball, run the following command as an
+administrative user::
+
+    python setup.py install
+
+
+pytz for Enterprise
+~~~~~~~~~~~~~~~~~~~
+
+Available as part of the Tidelift Subscription.
+
+The maintainers of pytz and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. `Learn more. <https://tidelift.com/subscription/pkg/pypi-pytz?utm_source=pypi-pytz&utm_medium=referral&utm_campaign=enterprise&utm_term=repo>`_.
+
+
+Example & Usage
+~~~~~~~~~~~~~~~
+
+Localized times and date arithmetic
+-----------------------------------
+
+>>> from datetime import datetime, timedelta
+>>> from pytz import timezone
+>>> import pytz
+>>> utc = pytz.utc
+>>> utc.zone
+'UTC'
+>>> eastern = timezone('US/Eastern')
+>>> eastern.zone
+'US/Eastern'
+>>> amsterdam = timezone('Europe/Amsterdam')
+>>> fmt = '%Y-%m-%d %H:%M:%S %Z%z'
+
+This library only supports two ways of building a localized time. The
+first is to use the ``localize()`` method provided by the pytz library.
+This is used to localize a naive datetime (datetime with no timezone
+information):
+
+>>> loc_dt = eastern.localize(datetime(2002, 10, 27, 6, 0, 0))
+>>> print(loc_dt.strftime(fmt))
+2002-10-27 06:00:00 EST-0500
+
+The second way of building a localized time is by converting an existing
+localized time using the standard ``astimezone()`` method:
+
+>>> ams_dt = loc_dt.astimezone(amsterdam)
+>>> ams_dt.strftime(fmt)
+'2002-10-27 12:00:00 CET+0100'
+
+Unfortunately using the tzinfo argument of the standard datetime
+constructors ''does not work'' with pytz for many timezones.
+
+>>> datetime(2002, 10, 27, 12, 0, 0, tzinfo=amsterdam).strftime(fmt)  # /!\ Does not work this way!
+'2002-10-27 12:00:00 LMT+0020'
+
+It is safe for timezones without daylight saving transitions though, such
+as UTC:
+
+>>> datetime(2002, 10, 27, 12, 0, 0, tzinfo=pytz.utc).strftime(fmt)  # /!\ Not recommended except for UTC
+'2002-10-27 12:00:00 UTC+0000'
+
+The preferred way of dealing with times is to always work in UTC,
+converting to localtime only when generating output to be read
+by humans.
+
+>>> utc_dt = datetime(2002, 10, 27, 6, 0, 0, tzinfo=utc)
+>>> loc_dt = utc_dt.astimezone(eastern)
+>>> loc_dt.strftime(fmt)
+'2002-10-27 01:00:00 EST-0500'
+
+This library also allows you to do date arithmetic using local
+times, although it is more complicated than working in UTC as you
+need to use the ``normalize()`` method to handle daylight saving time
+and other timezone transitions. In this example, ``loc_dt`` is set
+to the instant when daylight saving time ends in the US/Eastern
+timezone.
+
+>>> before = loc_dt - timedelta(minutes=10)
+>>> before.strftime(fmt)
+'2002-10-27 00:50:00 EST-0500'
+>>> eastern.normalize(before).strftime(fmt)
+'2002-10-27 01:50:00 EDT-0400'
+>>> after = eastern.normalize(before + timedelta(minutes=20))
+>>> after.strftime(fmt)
+'2002-10-27 01:10:00 EST-0500'
+
+Creating local times is also tricky, and the reason why working with
+local times is not recommended. Unfortunately, you cannot just pass
+a ``tzinfo`` argument when constructing a datetime (see the next
+section for more details)
+
+>>> dt = datetime(2002, 10, 27, 1, 30, 0)
+>>> dt1 = eastern.localize(dt, is_dst=True)
+>>> dt1.strftime(fmt)
+'2002-10-27 01:30:00 EDT-0400'
+>>> dt2 = eastern.localize(dt, is_dst=False)
+>>> dt2.strftime(fmt)
+'2002-10-27 01:30:00 EST-0500'
+
+Converting between timezones is more easily done, using the
+standard astimezone method.
+
+>>> utc_dt = utc.localize(datetime.utcfromtimestamp(1143408899))
+>>> utc_dt.strftime(fmt)
+'2006-03-26 21:34:59 UTC+0000'
+>>> au_tz = timezone('Australia/Sydney')
+>>> au_dt = utc_dt.astimezone(au_tz)
+>>> au_dt.strftime(fmt)
+'2006-03-27 08:34:59 AEDT+1100'
+>>> utc_dt2 = au_dt.astimezone(utc)
+>>> utc_dt2.strftime(fmt)
+'2006-03-26 21:34:59 UTC+0000'
+>>> utc_dt == utc_dt2
+True
+
+You can take shortcuts when dealing with the UTC side of timezone
+conversions. ``normalize()`` and ``localize()`` are not really
+necessary when there are no daylight saving time transitions to
+deal with.
+
+>>> utc_dt = datetime.utcfromtimestamp(1143408899).replace(tzinfo=utc)
+>>> utc_dt.strftime(fmt)
+'2006-03-26 21:34:59 UTC+0000'
+>>> au_tz = timezone('Australia/Sydney')
+>>> au_dt = au_tz.normalize(utc_dt.astimezone(au_tz))
+>>> au_dt.strftime(fmt)
+'2006-03-27 08:34:59 AEDT+1100'
+>>> utc_dt2 = au_dt.astimezone(utc)
+>>> utc_dt2.strftime(fmt)
+'2006-03-26 21:34:59 UTC+0000'
+
+
+``tzinfo`` API
+--------------
+
+The ``tzinfo`` instances returned by the ``timezone()`` function have
+been extended to cope with ambiguous times by adding an ``is_dst``
+parameter to the ``utcoffset()``, ``dst()`` && ``tzname()`` methods.
+
+>>> tz = timezone('America/St_Johns')
+
+>>> normal = datetime(2009, 9, 1)
+>>> ambiguous = datetime(2009, 10, 31, 23, 30)
+
+The ``is_dst`` parameter is ignored for most timestamps. It is only used
+during DST transition ambiguous periods to resolve that ambiguity.
+
+>>> print(tz.utcoffset(normal, is_dst=True))
+-1 day, 21:30:00
+>>> print(tz.dst(normal, is_dst=True))
+1:00:00
+>>> tz.tzname(normal, is_dst=True)
+'NDT'
+
+>>> print(tz.utcoffset(ambiguous, is_dst=True))
+-1 day, 21:30:00
+>>> print(tz.dst(ambiguous, is_dst=True))
+1:00:00
+>>> tz.tzname(ambiguous, is_dst=True)
+'NDT'
+
+>>> print(tz.utcoffset(normal, is_dst=False))
+-1 day, 21:30:00
+>>> tz.dst(normal, is_dst=False).seconds
+3600
+>>> tz.tzname(normal, is_dst=False)
+'NDT'
+
+>>> print(tz.utcoffset(ambiguous, is_dst=False))
+-1 day, 20:30:00
+>>> tz.dst(ambiguous, is_dst=False)
+datetime.timedelta(0)
+>>> tz.tzname(ambiguous, is_dst=False)
+'NST'
+
+If ``is_dst`` is not specified, ambiguous timestamps will raise
+an ``pytz.exceptions.AmbiguousTimeError`` exception.
+
+>>> print(tz.utcoffset(normal))
+-1 day, 21:30:00
+>>> print(tz.dst(normal))
+1:00:00
+>>> tz.tzname(normal)
+'NDT'
+
+>>> import pytz.exceptions
+>>> try:
+...     tz.utcoffset(ambiguous)
+... except pytz.exceptions.AmbiguousTimeError:
+...     print('pytz.exceptions.AmbiguousTimeError: %s' % ambiguous)
+pytz.exceptions.AmbiguousTimeError: 2009-10-31 23:30:00
+>>> try:
+...     tz.dst(ambiguous)
+... except pytz.exceptions.AmbiguousTimeError:
+...     print('pytz.exceptions.AmbiguousTimeError: %s' % ambiguous)
+pytz.exceptions.AmbiguousTimeError: 2009-10-31 23:30:00
+>>> try:
+...     tz.tzname(ambiguous)
+... except pytz.exceptions.AmbiguousTimeError:
+...     print('pytz.exceptions.AmbiguousTimeError: %s' % ambiguous)
+pytz.exceptions.AmbiguousTimeError: 2009-10-31 23:30:00
+
+
+Problems with Localtime
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The major problem we have to deal with is that certain datetimes
+may occur twice in a year. For example, in the US/Eastern timezone
+on the last Sunday morning in October, the following sequence
+happens:
+
+    - 01:00 EDT occurs
+    - 1 hour later, instead of 2:00am the clock is turned back 1 hour
+      and 01:00 happens again (this time 01:00 EST)
+
+In fact, every instant between 01:00 and 02:00 occurs twice. This means
+that if you try and create a time in the 'US/Eastern' timezone
+the standard datetime syntax, there is no way to specify if you meant
+before of after the end-of-daylight-saving-time transition. Using the
+pytz custom syntax, the best you can do is make an educated guess:
+
+>>> loc_dt = eastern.localize(datetime(2002, 10, 27, 1, 30, 00))
+>>> loc_dt.strftime(fmt)
+'2002-10-27 01:30:00 EST-0500'
+
+As you can see, the system has chosen one for you and there is a 50%
+chance of it being out by one hour. For some applications, this does
+not matter. However, if you are trying to schedule meetings with people
+in different timezones or analyze log files it is not acceptable.
+
+The best and simplest solution is to stick with using UTC.  The pytz
+package encourages using UTC for internal timezone representation by
+including a special UTC implementation based on the standard Python
+reference implementation in the Python documentation.
+
+The UTC timezone unpickles to be the same instance, and pickles to a
+smaller size than other pytz tzinfo instances.  The UTC implementation
+can be obtained as pytz.utc, pytz.UTC, or pytz.timezone('UTC').
+
+>>> import pickle, pytz
+>>> dt = datetime(2005, 3, 1, 14, 13, 21, tzinfo=utc)
+>>> naive = dt.replace(tzinfo=None)
+>>> p = pickle.dumps(dt, 1)
+>>> naive_p = pickle.dumps(naive, 1)
+>>> len(p) - len(naive_p)
+17
+>>> new = pickle.loads(p)
+>>> new == dt
+True
+>>> new is dt
+False
+>>> new.tzinfo is dt.tzinfo
+True
+>>> pytz.utc is pytz.UTC is pytz.timezone('UTC')
+True
+
+Note that some other timezones are commonly thought of as the same (GMT,
+Greenwich, Universal, etc.). The definition of UTC is distinct from these
+other timezones, and they are not equivalent. For this reason, they will
+not compare the same in Python.
+
+>>> utc == pytz.timezone('GMT')
+False
+
+See the section `What is UTC`_, below.
+
+If you insist on working with local times, this library provides a
+facility for constructing them unambiguously:
+
+>>> loc_dt = datetime(2002, 10, 27, 1, 30, 00)
+>>> est_dt = eastern.localize(loc_dt, is_dst=True)
+>>> edt_dt = eastern.localize(loc_dt, is_dst=False)
+>>> print(est_dt.strftime(fmt) + ' / ' + edt_dt.strftime(fmt))
+2002-10-27 01:30:00 EDT-0400 / 2002-10-27 01:30:00 EST-0500
+
+If you pass None as the is_dst flag to localize(), pytz will refuse to
+guess and raise exceptions if you try to build ambiguous or non-existent
+times.
+
+For example, 1:30am on 27th Oct 2002 happened twice in the US/Eastern
+timezone when the clocks where put back at the end of Daylight Saving
+Time:
+
+>>> dt = datetime(2002, 10, 27, 1, 30, 00)
+>>> try:
+...     eastern.localize(dt, is_dst=None)
+... except pytz.exceptions.AmbiguousTimeError:
+...     print('pytz.exceptions.AmbiguousTimeError: %s' % dt)
+pytz.exceptions.AmbiguousTimeError: 2002-10-27 01:30:00
+
+Similarly, 2:30am on 7th April 2002 never happened at all in the
+US/Eastern timezone, as the clocks where put forward at 2:00am skipping
+the entire hour:
+
+>>> dt = datetime(2002, 4, 7, 2, 30, 00)
+>>> try:
+...     eastern.localize(dt, is_dst=None)
+... except pytz.exceptions.NonExistentTimeError:
+...     print('pytz.exceptions.NonExistentTimeError: %s' % dt)
+pytz.exceptions.NonExistentTimeError: 2002-04-07 02:30:00
+
+Both of these exceptions share a common base class to make error handling
+easier:
+
+>>> isinstance(pytz.AmbiguousTimeError(), pytz.InvalidTimeError)
+True
+>>> isinstance(pytz.NonExistentTimeError(), pytz.InvalidTimeError)
+True
+
+
+A special case is where countries change their timezone definitions
+with no daylight savings time switch. For example, in 1915 Warsaw
+switched from Warsaw time to Central European time with no daylight savings
+transition. So at the stroke of midnight on August 5th 1915 the clocks
+were wound back 24 minutes creating an ambiguous time period that cannot
+be specified without referring to the timezone abbreviation or the
+actual UTC offset. In this case midnight happened twice, neither time
+during a daylight saving time period. pytz handles this transition by
+treating the ambiguous period before the switch as daylight savings
+time, and the ambiguous period after as standard time.
+
+
+>>> warsaw = pytz.timezone('Europe/Warsaw')
+>>> amb_dt1 = warsaw.localize(datetime(1915, 8, 4, 23, 59, 59), is_dst=True)
+>>> amb_dt1.strftime(fmt)
+'1915-08-04 23:59:59 WMT+0124'
+>>> amb_dt2 = warsaw.localize(datetime(1915, 8, 4, 23, 59, 59), is_dst=False)
+>>> amb_dt2.strftime(fmt)
+'1915-08-04 23:59:59 CET+0100'
+>>> switch_dt = warsaw.localize(datetime(1915, 8, 5, 00, 00, 00), is_dst=False)
+>>> switch_dt.strftime(fmt)
+'1915-08-05 00:00:00 CET+0100'
+>>> str(switch_dt - amb_dt1)
+'0:24:01'
+>>> str(switch_dt - amb_dt2)
+'0:00:01'
+
+The best way of creating a time during an ambiguous time period is
+by converting from another timezone such as UTC:
+
+>>> utc_dt = datetime(1915, 8, 4, 22, 36, tzinfo=pytz.utc)
+>>> utc_dt.astimezone(warsaw).strftime(fmt)
+'1915-08-04 23:36:00 CET+0100'
+
+The standard Python way of handling all these ambiguities is not to
+handle them, such as demonstrated in this example using the US/Eastern
+timezone definition from the Python documentation (Note that this
+implementation only works for dates between 1987 and 2006 - it is
+included for tests only!):
+
+>>> from pytz.reference import Eastern # pytz.reference only for tests
+>>> dt = datetime(2002, 10, 27, 0, 30, tzinfo=Eastern)
+>>> str(dt)
+'2002-10-27 00:30:00-04:00'
+>>> str(dt + timedelta(hours=1))
+'2002-10-27 01:30:00-05:00'
+>>> str(dt + timedelta(hours=2))
+'2002-10-27 02:30:00-05:00'
+>>> str(dt + timedelta(hours=3))
+'2002-10-27 03:30:00-05:00'
+
+Notice the first two results? At first glance you might think they are
+correct, but taking the UTC offset into account you find that they are
+actually two hours appart instead of the 1 hour we asked for.
+
+>>> from pytz.reference import UTC # pytz.reference only for tests
+>>> str(dt.astimezone(UTC))
+'2002-10-27 04:30:00+00:00'
+>>> str((dt + timedelta(hours=1)).astimezone(UTC))
+'2002-10-27 06:30:00+00:00'
+
+
+Country Information
+~~~~~~~~~~~~~~~~~~~
+
+A mechanism is provided to access the timezones commonly in use
+for a particular country, looked up using the ISO 3166 country code.
+It returns a list of strings that can be used to retrieve the relevant
+tzinfo instance using ``pytz.timezone()``:
+
+>>> print(' '.join(pytz.country_timezones['nz']))
+Pacific/Auckland Pacific/Chatham
+
+The Olson database comes with a ISO 3166 country code to English country
+name mapping that pytz exposes as a dictionary:
+
+>>> print(pytz.country_names['nz'])
+New Zealand
+
+
+What is UTC
+~~~~~~~~~~~
+
+'UTC' is `Coordinated Universal Time`_. It is a successor to, but distinct
+from, Greenwich Mean Time (GMT) and the various definitions of Universal
+Time. UTC is now the worldwide standard for regulating clocks and time
+measurement.
+
+All other timezones are defined relative to UTC, and include offsets like
+UTC+0800 - hours to add or subtract from UTC to derive the local time. No
+daylight saving time occurs in UTC, making it a useful timezone to perform
+date arithmetic without worrying about the confusion and ambiguities caused
+by daylight saving time transitions, your country changing its timezone, or
+mobile computers that roam through multiple timezones.
+
+..  _Coordinated Universal Time: https://en.wikipedia.org/wiki/Coordinated_Universal_Time
+
+
+Helpers
+~~~~~~~
+
+There are two lists of timezones provided.
+
+``all_timezones`` is the exhaustive list of the timezone names that can
+be used.
+
+>>> from pytz import all_timezones
+>>> len(all_timezones) >= 500
+True
+>>> 'Etc/Greenwich' in all_timezones
+True
+
+``common_timezones`` is a list of useful, current timezones. It doesn't
+contain deprecated zones or historical zones, except for a few I've
+deemed in common usage, such as US/Eastern (open a bug report if you
+think other timezones are deserving of being included here). It is also
+a sequence of strings.
+
+>>> from pytz import common_timezones
+>>> len(common_timezones) < len(all_timezones)
+True
+>>> 'Etc/Greenwich' in common_timezones
+False
+>>> 'Australia/Melbourne' in common_timezones
+True
+>>> 'US/Eastern' in common_timezones
+True
+>>> 'Canada/Eastern' in common_timezones
+True
+>>> 'Australia/Yancowinna' in all_timezones
+True
+>>> 'Australia/Yancowinna' in common_timezones
+False
+
+Both ``common_timezones`` and ``all_timezones`` are alphabetically
+sorted:
+
+>>> common_timezones_dupe = common_timezones[:]
+>>> common_timezones_dupe.sort()
+>>> common_timezones == common_timezones_dupe
+True
+>>> all_timezones_dupe = all_timezones[:]
+>>> all_timezones_dupe.sort()
+>>> all_timezones == all_timezones_dupe
+True
+
+``all_timezones`` and ``common_timezones`` are also available as sets.
+
+>>> from pytz import all_timezones_set, common_timezones_set
+>>> 'US/Eastern' in all_timezones_set
+True
+>>> 'US/Eastern' in common_timezones_set
+True
+>>> 'Australia/Victoria' in common_timezones_set
+False
+
+You can also retrieve lists of timezones used by particular countries
+using the ``country_timezones()`` function. It requires an ISO-3166
+two letter country code.
+
+>>> from pytz import country_timezones
+>>> print(' '.join(country_timezones('ch')))
+Europe/Zurich
+>>> print(' '.join(country_timezones('CH')))
+Europe/Zurich
+
+
+Internationalization - i18n/l10n
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Pytz is an interface to the IANA database, which uses ASCII names. The `Unicode  Consortium's Unicode Locales (CLDR) <http://cldr.unicode.org>`_
+project provides translations. Thomas Khyn's
+`l18n <https://pypi.org/project/l18n/>`_ package can be used to access
+these translations from Python.
+
+
+License
+~~~~~~~
+
+MIT license.
+
+This code is also available as part of Zope 3 under the Zope Public
+License,  Version 2.1 (ZPL).
+
+I'm happy to relicense this code if necessary for inclusion in other
+open source projects.
+
+
+Latest Versions
+~~~~~~~~~~~~~~~
+
+This package will be updated after releases of the Olson timezone
+database.  The latest version can be downloaded from the `Python Package
+Index <https://pypi.org/project/pytz/>`_.  The code that is used
+to generate this distribution is hosted on launchpad.net and available
+using git::
+
+    git clone https://git.launchpad.net/pytz
+
+A mirror on github is also available at https://github.com/stub42/pytz
+
+Announcements of new releases are made on
+`Launchpad <https://launchpad.net/pytz>`_, and the
+`Atom feed <http://feeds.launchpad.net/pytz/announcements.atom>`_
+hosted there.
+
+
+Bugs, Feature Requests & Patches
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Bugs can be reported using `Launchpad Bugs <https://bugs.launchpad.net/pytz>`_.
+
+
+Security Issues
+~~~~~~~~~~~~~~~
+
+Reports about security issues can be made via `Tidelift <https://tidelift.com/security>`_.
+
+
+Issues & Limitations
+~~~~~~~~~~~~~~~~~~~~
+
+- Offsets from UTC are rounded to the nearest whole minute, so timezones
+  such as Europe/Amsterdam pre 1937 will be up to 30 seconds out. This
+  is a limitation of the Python datetime library.
+
+- If you think a timezone definition is incorrect, I probably can't fix
+  it. pytz is a direct translation of the Olson timezone database, and
+  changes to the timezone definitions need to be made to this source.
+  If you find errors they should be reported to the time zone mailing
+  list, linked from http://www.iana.org/time-zones.
+
+
+Further Reading
+~~~~~~~~~~~~~~~
+
+More info than you want to know about timezones:
+http://www.twinsun.com/tz/tz-link.htm
+
+
+Contact
+~~~~~~~
+
+Stuart Bishop <stuart@stuartbishop.net>
+
+
diff --git a/src/pytz/__init__.py b/src/pytz/__init__.py
new file mode 100644
index 0000000..50c5b55
--- /dev/null
+++ b/src/pytz/__init__.py
@@ -0,0 +1,516 @@
+'''
+datetime.tzinfo timezone definitions generated from the
+Olson timezone database:
+
+    ftp://elsie.nci.nih.gov/pub/tz*.tar.gz
+
+See the datetime section of the Python Library Reference for information
+on how to use these modules.
+'''
+
+import sys
+import datetime
+import os.path
+
+from pytz.exceptions import AmbiguousTimeError
+from pytz.exceptions import InvalidTimeError
+from pytz.exceptions import NonExistentTimeError
+from pytz.exceptions import UnknownTimeZoneError
+from pytz.lazy import LazyDict, LazyList, LazySet  # noqa
+from pytz.tzinfo import unpickler, BaseTzInfo
+from pytz.tzfile import build_tzinfo
+
+
+# The IANA (nee Olson) database is updated several times a year.
+OLSON_VERSION = '2021c'
+VERSION = '2021.3'  # pip compatible version number.
+__version__ = VERSION
+
+OLSEN_VERSION = OLSON_VERSION  # Old releases had this misspelling
+
+__all__ = [
+    'timezone', 'utc', 'country_timezones', 'country_names',
+    'AmbiguousTimeError', 'InvalidTimeError',
+    'NonExistentTimeError', 'UnknownTimeZoneError',
+    'all_timezones', 'all_timezones_set',
+    'common_timezones', 'common_timezones_set',
+    'BaseTzInfo', 'FixedOffset',
+]
+
+
+if sys.version_info[0] > 2:  # Python 3.x
+
+    # Python 3.x doesn't have unicode(), making writing code
+    # for Python 2.3 and Python 3.x a pain.
+    unicode = str
+
+    def ascii(s):
+        r"""
+        >>> ascii('Hello')
+        'Hello'
+        >>> ascii('\N{TRADE MARK SIGN}') #doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+            ...
+        UnicodeEncodeError: ...
+        """
+        if type(s) == bytes:
+            s = s.decode('ASCII')
+        else:
+            s.encode('ASCII')  # Raise an exception if not ASCII
+        return s  # But the string - not a byte string.
+
+else:  # Python 2.x
+
+    def ascii(s):
+        r"""
+        >>> ascii('Hello')
+        'Hello'
+        >>> ascii(u'Hello')
+        'Hello'
+        >>> ascii(u'\N{TRADE MARK SIGN}') #doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+            ...
+        UnicodeEncodeError: ...
+        """
+        return s.encode('ASCII')
+
+
+def open_resource(name):
+    """Open a resource from the zoneinfo subdir for reading.
+
+    Uses the pkg_resources module if available and no standard file
+    found at the calculated location.
+
+    It is possible to specify different location for zoneinfo
+    subdir by using the PYTZ_TZDATADIR environment variable.
+    """
+    name_parts = name.lstrip('/').split('/')
+    for part in name_parts:
+        if part == os.path.pardir or os.path.sep in part:
+            raise ValueError('Bad path segment: %r' % part)
+    zoneinfo_dir = os.environ.get('PYTZ_TZDATADIR', None)
+    if zoneinfo_dir is not None:
+        filename = os.path.join(zoneinfo_dir, *name_parts)
+    else:
+        filename = os.path.join(os.path.dirname(__file__),
+                                'zoneinfo', *name_parts)
+        if not os.path.exists(filename):
+            # http://bugs.launchpad.net/bugs/383171 - we avoid using this
+            # unless absolutely necessary to help when a broken version of
+            # pkg_resources is installed.
+            try:
+                from pkg_resources import resource_stream
+            except ImportError:
+                resource_stream = None
+
+            if resource_stream is not None:
+                return resource_stream(__name__, 'zoneinfo/' + name)
+    return open(filename, 'rb')
+
+
+def resource_exists(name):
+    """Return true if the given resource exists"""
+    try:
+        if os.environ.get('PYTZ_SKIPEXISTSCHECK', ''):
+            # In "standard" distributions, we can assume that
+            # all the listed timezones are present. As an
+            # import-speed optimization, you can set the
+            # PYTZ_SKIPEXISTSCHECK flag to skip checking
+            # for the presence of the resource file on disk.
+            return True
+        open_resource(name).close()
+        return True
+    except IOError:
+        return False
+
+
+_tzinfo_cache = {}
+
+
+def timezone(zone):
+    r''' Return a datetime.tzinfo implementation for the given timezone
+
+    >>> from datetime import datetime, timedelta
+    >>> utc = timezone('UTC')
+    >>> eastern = timezone('US/Eastern')
+    >>> eastern.zone
+    'US/Eastern'
+    >>> timezone(unicode('US/Eastern')) is eastern
+    True
+    >>> utc_dt = datetime(2002, 10, 27, 6, 0, 0, tzinfo=utc)
+    >>> loc_dt = utc_dt.astimezone(eastern)
+    >>> fmt = '%Y-%m-%d %H:%M:%S %Z (%z)'
+    >>> loc_dt.strftime(fmt)
+    '2002-10-27 01:00:00 EST (-0500)'
+    >>> (loc_dt - timedelta(minutes=10)).strftime(fmt)
+    '2002-10-27 00:50:00 EST (-0500)'
+    >>> eastern.normalize(loc_dt - timedelta(minutes=10)).strftime(fmt)
+    '2002-10-27 01:50:00 EDT (-0400)'
+    >>> (loc_dt + timedelta(minutes=10)).strftime(fmt)
+    '2002-10-27 01:10:00 EST (-0500)'
+
+    Raises UnknownTimeZoneError if passed an unknown zone.
+
+    >>> try:
+    ...     timezone('Asia/Shangri-La')
+    ... except UnknownTimeZoneError:
+    ...     print('Unknown')
+    Unknown
+
+    >>> try:
+    ...     timezone(unicode('\N{TRADE MARK SIGN}'))
+    ... except UnknownTimeZoneError:
+    ...     print('Unknown')
+    Unknown
+
+    '''
+    if zone is None:
+        raise UnknownTimeZoneError(None)
+
+    if zone.upper() == 'UTC':
+        return utc
+
+    try:
+        zone = ascii(zone)
+    except UnicodeEncodeError:
+        # All valid timezones are ASCII
+        raise UnknownTimeZoneError(zone)
+
+    zone = _case_insensitive_zone_lookup(_unmunge_zone(zone))
+    if zone not in _tzinfo_cache:
+        if zone in all_timezones_set:  # noqa
+            fp = open_resource(zone)
+            try:
+                _tzinfo_cache[zone] = build_tzinfo(zone, fp)
+            finally:
+                fp.close()
+        else:
+            raise UnknownTimeZoneError(zone)
+
+    return _tzinfo_cache[zone]
+
+
+def _unmunge_zone(zone):
+    """Undo the time zone name munging done by older versions of pytz."""
+    return zone.replace('_plus_', '+').replace('_minus_', '-')
+
+
+_all_timezones_lower_to_standard = None
+
+
+def _case_insensitive_zone_lookup(zone):
+    """case-insensitively matching timezone, else return zone unchanged"""
+    global _all_timezones_lower_to_standard
+    if _all_timezones_lower_to_standard is None:
+        _all_timezones_lower_to_standard = dict((tz.lower(), tz) for tz in all_timezones)  # noqa
+    return _all_timezones_lower_to_standard.get(zone.lower()) or zone  # noqa
+
+
+ZERO = datetime.timedelta(0)
+HOUR = datetime.timedelta(hours=1)
+
+
+class UTC(BaseTzInfo):
+    """UTC
+
+    Optimized UTC implementation. It unpickles using the single module global
+    instance defined beneath this class declaration.
+    """
+    zone = "UTC"
+
+    _utcoffset = ZERO
+    _dst = ZERO
+    _tzname = zone
+
+    def fromutc(self, dt):
+        if dt.tzinfo is None:
+            return self.localize(dt)
+        return super(utc.__class__, self).fromutc(dt)
+
+    def utcoffset(self, dt):
+        return ZERO
+
+    def tzname(self, dt):
+        return "UTC"
+
+    def dst(self, dt):
+        return ZERO
+
+    def __reduce__(self):
+        return _UTC, ()
+
+    def localize(self, dt, is_dst=False):
+        '''Convert naive time to local time'''
+        if dt.tzinfo is not None:
+            raise ValueError('Not naive datetime (tzinfo is already set)')
+        return dt.replace(tzinfo=self)
+
+    def normalize(self, dt, is_dst=False):
+        '''Correct the timezone information on the given datetime'''
+        if dt.tzinfo is self:
+            return dt
+        if dt.tzinfo is None:
+            raise ValueError('Naive time - no tzinfo set')
+        return dt.astimezone(self)
+
+    def __repr__(self):
+        return "<UTC>"
+
+    def __str__(self):
+        return "UTC"
+
+
+UTC = utc = UTC()  # UTC is a singleton
+
+
+def _UTC():
+    """Factory function for utc unpickling.
+
+    Makes sure that unpickling a utc instance always returns the same
+    module global.
+
+    These examples belong in the UTC class above, but it is obscured; or in
+    the README.rst, but we are not depending on Python 2.4 so integrating
+    the README.rst examples with the unit tests is not trivial.
+
+    >>> import datetime, pickle
+    >>> dt = datetime.datetime(2005, 3, 1, 14, 13, 21, tzinfo=utc)
+    >>> naive = dt.replace(tzinfo=None)
+    >>> p = pickle.dumps(dt, 1)
+    >>> naive_p = pickle.dumps(naive, 1)
+    >>> len(p) - len(naive_p)
+    17
+    >>> new = pickle.loads(p)
+    >>> new == dt
+    True
+    >>> new is dt
+    False
+    >>> new.tzinfo is dt.tzinfo
+    True
+    >>> utc is UTC is timezone('UTC')
+    True
+    >>> utc is timezone('GMT')
+    False
+    """
+    return utc
+
+
+_UTC.__safe_for_unpickling__ = True
+
+
+def _p(*args):
+    """Factory function for unpickling pytz tzinfo instances.
+
+    Just a wrapper around tzinfo.unpickler to save a few bytes in each pickle
+    by shortening the path.
+    """
+    return unpickler(*args)
+
+
+_p.__safe_for_unpickling__ = True
+
+
+class _CountryTimezoneDict(LazyDict):
+    """Map ISO 3166 country code to a list of timezone names commonly used
+    in that country.
+
+    iso3166_code is the two letter code used to identify the country.
+
+    >>> def print_list(list_of_strings):
+    ...     'We use a helper so doctests work under Python 2.3 -> 3.x'
+    ...     for s in list_of_strings:
+    ...         print(s)
+
+    >>> print_list(country_timezones['nz'])
+    Pacific/Auckland
+    Pacific/Chatham
+    >>> print_list(country_timezones['ch'])
+    Europe/Zurich
+    >>> print_list(country_timezones['CH'])
+    Europe/Zurich
+    >>> print_list(country_timezones[unicode('ch')])
+    Europe/Zurich
+    >>> print_list(country_timezones['XXX'])
+    Traceback (most recent call last):
+    ...
+    KeyError: 'XXX'
+
+    Previously, this information was exposed as a function rather than a
+    dictionary. This is still supported::
+
+    >>> print_list(country_timezones('nz'))
+    Pacific/Auckland
+    Pacific/Chatham
+    """
+    def __call__(self, iso3166_code):
+        """Backwards compatibility."""
+        return self[iso3166_code]
+
+    def _fill(self):
+        data = {}
+        zone_tab = open_resource('zone.tab')
+        try:
+            for line in zone_tab:
+                line = line.decode('UTF-8')
+                if line.startswith('#'):
+                    continue
+                code, coordinates, zone = line.split(None, 4)[:3]
+                if zone not in all_timezones_set:  # noqa
+                    continue
+                try:
+                    data[code].append(zone)
+                except KeyError:
+                    data[code] = [zone]
+            self.data = data
+        finally:
+            zone_tab.close()
+
+
+country_timezones = _CountryTimezoneDict()
+
+
+class _CountryNameDict(LazyDict):
+    '''Dictionary proving ISO3166 code -> English name.
+
+    >>> print(country_names['au'])
+    Australia
+    '''
+    def _fill(self):
+        data = {}
+        zone_tab = open_resource('iso3166.tab')
+        try:
+            for line in zone_tab.readlines():
+                line = line.decode('UTF-8')
+                if line.startswith('#'):
+                    continue
+                code, name = line.split(None, 1)
+                data[code] = name.strip()
+            self.data = data
+        finally:
+            zone_tab.close()
+
+
+country_names = _CountryNameDict()
+
+
+# Time-zone info based solely on fixed offsets
+
+class _FixedOffset(datetime.tzinfo):
+
+    zone = None  # to match the standard pytz API
+
+    def __init__(self, minutes):
+        if abs(minutes) >= 1440:
+            raise ValueError("absolute offset is too large", minutes)
+        self._minutes = minutes
+        self._offset = datetime.timedelta(minutes=minutes)
+
+    def utcoffset(self, dt):
+        return self._offset
+
+    def __reduce__(self):
+        return FixedOffset, (self._minutes, )
+
+    def dst(self, dt):
+        return ZERO
+
+    def tzname(self, dt):
+        return None
+
+    def __repr__(self):
+        return 'pytz.FixedOffset(%d)' % self._minutes
+
+    def localize(self, dt, is_dst=False):
+        '''Convert naive time to local time'''
+        if dt.tzinfo is not None:
+            raise ValueError('Not naive datetime (tzinfo is already set)')
+        return dt.replace(tzinfo=self)
+
+    def normalize(self, dt, is_dst=False):
+        '''Correct the timezone information on the given datetime'''
+        if dt.tzinfo is self:
+            return dt
+        if dt.tzinfo is None:
+            raise ValueError('Naive time - no tzinfo set')
+        return dt.astimezone(self)
+
+
+def FixedOffset(offset, _tzinfos={}):
+    """return a fixed-offset timezone based off a number of minutes.
+
+        >>> one = FixedOffset(-330)
+        >>> one
+        pytz.FixedOffset(-330)
+        >>> str(one.utcoffset(datetime.datetime.now()))
+        '-1 day, 18:30:00'
+        >>> str(one.dst(datetime.datetime.now()))
+        '0:00:00'
+
+        >>> two = FixedOffset(1380)
+        >>> two
+        pytz.FixedOffset(1380)
+        >>> str(two.utcoffset(datetime.datetime.now()))
+        '23:00:00'
+        >>> str(two.dst(datetime.datetime.now()))
+        '0:00:00'
+
+    The datetime.timedelta must be between the range of -1 and 1 day,
+    non-inclusive.
+
+        >>> FixedOffset(1440)
+        Traceback (most recent call last):
+        ...
+        ValueError: ('absolute offset is too large', 1440)
+
+        >>> FixedOffset(-1440)
+        Traceback (most recent call last):
+        ...
+        ValueError: ('absolute offset is too large', -1440)
+
+    An offset of 0 is special-cased to return UTC.
+
+        >>> FixedOffset(0) is UTC
+        True
+
+    There should always be only one instance of a FixedOffset per timedelta.
+    This should be true for multiple creation calls.
+
+        >>> FixedOffset(-330) is one
+        True
+        >>> FixedOffset(1380) is two
+        True
+
+    It should also be true for pickling.
+
+        >>> import pickle
+        >>> pickle.loads(pickle.dumps(one)) is one
+        True
+        >>> pickle.loads(pickle.dumps(two)) is two
+        True
+    """
+    if offset == 0:
+        return UTC
+
+    info = _tzinfos.get(offset)
+    if info is None:
+        # We haven't seen this one before. we need to save it.
+
+        # Use setdefault to avoid a race condition and make sure we have
+        # only one
+        info = _tzinfos.setdefault(offset, _FixedOffset(offset))
+
+    return info
+
+
+FixedOffset.__safe_for_unpickling__ = True
+
+
+def _test():
+    import doctest
+    sys.path.insert(0, os.pardir)
+    import pytz
+    return doctest.testmod(pytz)
+
+
+if __name__ == '__main__':
+    _test()
diff --git a/src/pytz/exceptions.py b/src/pytz/exceptions.py
new file mode 100644
index 0000000..4b20bde
--- /dev/null
+++ b/src/pytz/exceptions.py
@@ -0,0 +1,59 @@
+'''
+Custom exceptions raised by pytz.
+'''
+
+__all__ = [
+    'UnknownTimeZoneError', 'InvalidTimeError', 'AmbiguousTimeError',
+    'NonExistentTimeError',
+]
+
+
+class Error(Exception):
+    '''Base class for all exceptions raised by the pytz library'''
+
+
+class UnknownTimeZoneError(KeyError, Error):
+    '''Exception raised when pytz is passed an unknown timezone.
+
+    >>> isinstance(UnknownTimeZoneError(), LookupError)
+    True
+
+    This class is actually a subclass of KeyError to provide backwards
+    compatibility with code relying on the undocumented behavior of earlier
+    pytz releases.
+
+    >>> isinstance(UnknownTimeZoneError(), KeyError)
+    True
+
+    And also a subclass of pytz.exceptions.Error, as are other pytz
+    exceptions.
+
+    >>> isinstance(UnknownTimeZoneError(), Error)
+    True
+
+    '''
+    pass
+
+
+class InvalidTimeError(Error):
+    '''Base class for invalid time exceptions.'''
+
+
+class AmbiguousTimeError(InvalidTimeError):
+    '''Exception raised when attempting to create an ambiguous wallclock time.
+
+    At the end of a DST transition period, a particular wallclock time will
+    occur twice (once before the clocks are set back, once after). Both
+    possibilities may be correct, unless further information is supplied.
+
+    See DstTzInfo.normalize() for more info
+    '''
+
+
+class NonExistentTimeError(InvalidTimeError):
+    '''Exception raised when attempting to create a wallclock time that
+    cannot exist.
+
+    At the start of a DST transition period, the wallclock time jumps forward.
+    The instants jumped over never occur.
+    '''
diff --git a/src/pytz/lazy.py b/src/pytz/lazy.py
new file mode 100644
index 0000000..39344fc
--- /dev/null
+++ b/src/pytz/lazy.py
@@ -0,0 +1,172 @@
+from threading import RLock
+try:
+    from collections.abc import Mapping as DictMixin
+except ImportError:  # Python < 3.3
+    try:
+        from UserDict import DictMixin  # Python 2
+    except ImportError:  # Python 3.0-3.3
+        from collections import Mapping as DictMixin
+
+
+# With lazy loading, we might end up with multiple threads triggering
+# it at the same time. We need a lock.
+_fill_lock = RLock()
+
+
+class LazyDict(DictMixin):
+    """Dictionary populated on first use."""
+    data = None
+
+    def __getitem__(self, key):
+        if self.data is None:
+            _fill_lock.acquire()
+            try:
+                if self.data is None:
+                    self._fill()
+            finally:
+                _fill_lock.release()
+        return self.data[key.upper()]
+
+    def __contains__(self, key):
+        if self.data is None:
+            _fill_lock.acquire()
+            try:
+                if self.data is None:
+                    self._fill()
+            finally:
+                _fill_lock.release()
+        return key in self.data
+
+    def __iter__(self):
+        if self.data is None:
+            _fill_lock.acquire()
+            try:
+                if self.data is None:
+                    self._fill()
+            finally:
+                _fill_lock.release()
+        return iter(self.data)
+
+    def __len__(self):
+        if self.data is None:
+            _fill_lock.acquire()
+            try:
+                if self.data is None:
+                    self._fill()
+            finally:
+                _fill_lock.release()
+        return len(self.data)
+
+    def keys(self):
+        if self.data is None:
+            _fill_lock.acquire()
+            try:
+                if self.data is None:
+                    self._fill()
+            finally:
+                _fill_lock.release()
+        return self.data.keys()
+
+
+class LazyList(list):
+    """List populated on first use."""
+
+    _props = [
+        '__str__', '__repr__', '__unicode__',
+        '__hash__', '__sizeof__', '__cmp__',
+        '__lt__', '__le__', '__eq__', '__ne__', '__gt__', '__ge__',
+        'append', 'count', 'index', 'extend', 'insert', 'pop', 'remove',
+        'reverse', 'sort', '__add__', '__radd__', '__iadd__', '__mul__',
+        '__rmul__', '__imul__', '__contains__', '__len__', '__nonzero__',
+        '__getitem__', '__setitem__', '__delitem__', '__iter__',
+        '__reversed__', '__getslice__', '__setslice__', '__delslice__']
+
+    def __new__(cls, fill_iter=None):
+
+        if fill_iter is None:
+            return list()
+
+        # We need a new class as we will be dynamically messing with its
+        # methods.
+        class LazyList(list):
+            pass
+
+        fill_iter = [fill_iter]
+
+        def lazy(name):
+            def _lazy(self, *args, **kw):
+                _fill_lock.acquire()
+                try:
+                    if len(fill_iter) > 0:
+                        list.extend(self, fill_iter.pop())
+                        for method_name in cls._props:
+                            delattr(LazyList, method_name)
+                finally:
+                    _fill_lock.release()
+                return getattr(list, name)(self, *args, **kw)
+            return _lazy
+
+        for name in cls._props:
+            setattr(LazyList, name, lazy(name))
+
+        new_list = LazyList()
+        return new_list
+
+# Not all versions of Python declare the same magic methods.
+# Filter out properties that don't exist in this version of Python
+# from the list.
+LazyList._props = [prop for prop in LazyList._props if hasattr(list, prop)]
+
+
+class LazySet(set):
+    """Set populated on first use."""
+
+    _props = (
+        '__str__', '__repr__', '__unicode__',
+        '__hash__', '__sizeof__', '__cmp__',
+        '__lt__', '__le__', '__eq__', '__ne__', '__gt__', '__ge__',
+        '__contains__', '__len__', '__nonzero__',
+        '__getitem__', '__setitem__', '__delitem__', '__iter__',
+        '__sub__', '__and__', '__xor__', '__or__',
+        '__rsub__', '__rand__', '__rxor__', '__ror__',
+        '__isub__', '__iand__', '__ixor__', '__ior__',
+        'add', 'clear', 'copy', 'difference', 'difference_update',
+        'discard', 'intersection', 'intersection_update', 'isdisjoint',
+        'issubset', 'issuperset', 'pop', 'remove',
+        'symmetric_difference', 'symmetric_difference_update',
+        'union', 'update')
+
+    def __new__(cls, fill_iter=None):
+
+        if fill_iter is None:
+            return set()
+
+        class LazySet(set):
+            pass
+
+        fill_iter = [fill_iter]
+
+        def lazy(name):
+            def _lazy(self, *args, **kw):
+                _fill_lock.acquire()
+                try:
+                    if len(fill_iter) > 0:
+                        for i in fill_iter.pop():
+                            set.add(self, i)
+                        for method_name in cls._props:
+                            delattr(LazySet, method_name)
+                finally:
+                    _fill_lock.release()
+                return getattr(set, name)(self, *args, **kw)
+            return _lazy
+
+        for name in cls._props:
+            setattr(LazySet, name, lazy(name))
+
+        new_set = LazySet()
+        return new_set
+
+# Not all versions of Python declare the same magic methods.
+# Filter out properties that don't exist in this version of Python
+# from the list.
+LazySet._props = [prop for prop in LazySet._props if hasattr(set, prop)]
diff --git a/src/pytz/locales/pytz.pot b/src/pytz/locales/pytz.pot
new file mode 100644
index 0000000..9c76c11
--- /dev/null
+++ b/src/pytz/locales/pytz.pot
@@ -0,0 +1,2 @@
+# This file will be generated by gen_pot.py. This is just a stub to keep
+# things working when this generated file is not available.
diff --git a/src/pytz/reference.py b/src/pytz/reference.py
new file mode 100644
index 0000000..f765ca0
--- /dev/null
+++ b/src/pytz/reference.py
@@ -0,0 +1,140 @@
+'''
+Reference tzinfo implementations from the Python docs.
+Used for testing against as they are only correct for the years
+1987 to 2006. Do not use these for real code.
+'''
+
+from datetime import tzinfo, timedelta, datetime
+from pytz import HOUR, ZERO, UTC
+
+__all__ = [
+    'FixedOffset',
+    'LocalTimezone',
+    'USTimeZone',
+    'Eastern',
+    'Central',
+    'Mountain',
+    'Pacific',
+    'UTC'
+]
+
+
+# A class building tzinfo objects for fixed-offset time zones.
+# Note that FixedOffset(0, "UTC") is a different way to build a
+# UTC tzinfo object.
+class FixedOffset(tzinfo):
+    """Fixed offset in minutes east from UTC."""
+
+    def __init__(self, offset, name):
+        self.__offset = timedelta(minutes=offset)
+        self.__name = name
+
+    def utcoffset(self, dt):
+        return self.__offset
+
+    def tzname(self, dt):
+        return self.__name
+
+    def dst(self, dt):
+        return ZERO
+
+
+import time as _time
+
+STDOFFSET = timedelta(seconds=-_time.timezone)
+if _time.daylight:
+    DSTOFFSET = timedelta(seconds=-_time.altzone)
+else:
+    DSTOFFSET = STDOFFSET
+
+DSTDIFF = DSTOFFSET - STDOFFSET
+
+
+# A class capturing the platform's idea of local time.
+class LocalTimezone(tzinfo):
+
+    def utcoffset(self, dt):
+        if self._isdst(dt):
+            return DSTOFFSET
+        else:
+            return STDOFFSET
+
+    def dst(self, dt):
+        if self._isdst(dt):
+            return DSTDIFF
+        else:
+            return ZERO
+
+    def tzname(self, dt):
+        return _time.tzname[self._isdst(dt)]
+
+    def _isdst(self, dt):
+        tt = (dt.year, dt.month, dt.day,
+              dt.hour, dt.minute, dt.second,
+              dt.weekday(), 0, -1)
+        stamp = _time.mktime(tt)
+        tt = _time.localtime(stamp)
+        return tt.tm_isdst > 0
+
+Local = LocalTimezone()
+
+
+def first_sunday_on_or_after(dt):
+    days_to_go = 6 - dt.weekday()
+    if days_to_go:
+        dt += timedelta(days_to_go)
+    return dt
+
+
+# In the US, DST starts at 2am (standard time) on the first Sunday in April.
+DSTSTART = datetime(1, 4, 1, 2)
+# and ends at 2am (DST time; 1am standard time) on the last Sunday of Oct.
+# which is the first Sunday on or after Oct 25.
+DSTEND = datetime(1, 10, 25, 1)
+
+
+# A complete implementation of current DST rules for major US time zones.
+class USTimeZone(tzinfo):
+
+    def __init__(self, hours, reprname, stdname, dstname):
+        self.stdoffset = timedelta(hours=hours)
+        self.reprname = reprname
+        self.stdname = stdname
+        self.dstname = dstname
+
+    def __repr__(self):
+        return self.reprname
+
+    def tzname(self, dt):
+        if self.dst(dt):
+            return self.dstname
+        else:
+            return self.stdname
+
+    def utcoffset(self, dt):
+        return self.stdoffset + self.dst(dt)
+
+    def dst(self, dt):
+        if dt is None or dt.tzinfo is None:
+            # An exception may be sensible here, in one or both cases.
+            # It depends on how you want to treat them.  The default
+            # fromutc() implementation (called by the default astimezone()
+            # implementation) passes a datetime with dt.tzinfo is self.
+            return ZERO
+        assert dt.tzinfo is self
+
+        # Find first Sunday in April & the last in October.
+        start = first_sunday_on_or_after(DSTSTART.replace(year=dt.year))
+        end = first_sunday_on_or_after(DSTEND.replace(year=dt.year))
+
+        # Can't compare naive to aware objects, so strip the timezone from
+        # dt first.
+        if start <= dt.replace(tzinfo=None) < end:
+            return HOUR
+        else:
+            return ZERO
+
+Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
+Central = USTimeZone(-6, "Central", "CST", "CDT")
+Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
+Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")
diff --git a/src/pytz/tests/test_docs.py b/src/pytz/tests/test_docs.py
new file mode 100644
index 0000000..d3b4b94
--- /dev/null
+++ b/src/pytz/tests/test_docs.py
@@ -0,0 +1,34 @@
+# -*- coding: ascii -*-
+
+from doctest import DocFileSuite
+import unittest
+import os.path
+import sys
+
+THIS_DIR = os.path.dirname(__file__)
+
+README = os.path.join(THIS_DIR, os.pardir, os.pardir, 'README.rst')
+
+
+class DocumentationTestCase(unittest.TestCase):
+    def test_readme_encoding(self):
+        '''Confirm the README.rst is ASCII.'''
+        f = open(README, 'rb')
+        try:
+            f.read().decode('ASCII')
+        finally:
+            f.close()
+
+
+def test_suite():
+    "For the Z3 test runner"
+    return unittest.TestSuite((
+        DocumentationTestCase('test_readme_encoding'),
+        DocFileSuite(os.path.join(os.pardir, os.pardir, 'README.rst'))))
+
+
+if __name__ == '__main__':
+    sys.path.insert(
+        0, os.path.abspath(os.path.join(THIS_DIR, os.pardir, os.pardir))
+    )
+    unittest.main(defaultTest='test_suite')
diff --git a/src/pytz/tests/test_lazy.py b/src/pytz/tests/test_lazy.py
new file mode 100644
index 0000000..3709703
--- /dev/null
+++ b/src/pytz/tests/test_lazy.py
@@ -0,0 +1,315 @@
+from operator import (
+    eq, ge, gt, le, lt, ne, add, concat, not_, sub, and_, or_, xor
+)
+import os.path
+import sys
+import unittest
+import warnings
+
+
+if __name__ == '__main__':
+    # Only munge path if invoked as a script. Testrunners should have setup
+    # the paths already
+    sys.path.insert(0, os.path.abspath(os.path.join(os.pardir, os.pardir)))
+
+
+from pytz.lazy import LazyList, LazySet
+
+
+class LazyListTestCase(unittest.TestCase):
+    initial_data = [3, 2, 1]
+
+    def setUp(self):
+        self.base = [3, 2, 1]
+        self.lesser = [2, 1, 0]
+        self.greater = [4, 3, 2]
+
+        self.lazy = LazyList(iter(list(self.base)))
+
+    def test_unary_ops(self):
+        unary_ops = [str, repr, len, bool, not_]
+        try:
+            unary_ops.append(unicode)
+        except NameError:
+            pass  # unicode no longer exists in Python 3.
+
+        for op in unary_ops:
+            self.assertEqual(
+                op(self.lazy),
+                op(self.base), str(op))
+
+    def test_binary_ops(self):
+        binary_ops = [eq, ge, gt, le, lt, ne, add, concat]
+        try:
+            binary_ops.append(cmp)
+        except NameError:
+            pass  # cmp no longer exists in Python 3.
+
+        for op in binary_ops:
+            self.assertEqual(
+                op(self.lazy, self.lazy),
+                op(self.base, self.base), str(op))
+            for other in [self.base, self.lesser, self.greater]:
+                self.assertEqual(
+                    op(self.lazy, other),
+                    op(self.base, other), '%s %s' % (op, other))
+                self.assertEqual(
+                    op(other, self.lazy),
+                    op(other, self.base), '%s %s' % (op, other))
+
+        # Multiplication
+        self.assertEqual(self.lazy * 3, self.base * 3)
+        self.assertEqual(3 * self.lazy, 3 * self.base)
+
+        # Contains
+        self.assertTrue(2 in self.lazy)
+        self.assertFalse(42 in self.lazy)
+
+    def test_iadd(self):
+        self.lazy += [1]
+        self.base += [1]
+        self.assertEqual(self.lazy, self.base)
+
+    def test_bool(self):
+        self.assertTrue(bool(self.lazy))
+        self.assertFalse(bool(LazyList()))
+        self.assertFalse(bool(LazyList(iter([]))))
+
+    def test_hash(self):
+        self.assertRaises(TypeError, hash, self.lazy)
+
+    def test_isinstance(self):
+        self.assertTrue(isinstance(self.lazy, list))
+        self.assertFalse(isinstance(self.lazy, tuple))
+
+    def test_callable(self):
+        try:
+            callable
+        except NameError:
+            return  # No longer exists with Python 3.
+        self.assertFalse(callable(self.lazy))
+
+    def test_append(self):
+        self.base.append('extra')
+        self.lazy.append('extra')
+        self.assertEqual(self.lazy, self.base)
+
+    def test_count(self):
+        self.assertEqual(self.lazy.count(2), 1)
+
+    def test_index(self):
+        self.assertEqual(self.lazy.index(2), 1)
+
+    def test_extend(self):
+        self.base.extend([6, 7])
+        self.lazy.extend([6, 7])
+        self.assertEqual(self.lazy, self.base)
+
+    def test_insert(self):
+        self.base.insert(0, 'ping')
+        self.lazy.insert(0, 'ping')
+        self.assertEqual(self.lazy, self.base)
+
+    def test_pop(self):
+        self.assertEqual(self.lazy.pop(), self.base.pop())
+        self.assertEqual(self.lazy, self.base)
+
+    def test_remove(self):
+        self.base.remove(2)
+        self.lazy.remove(2)
+        self.assertEqual(self.lazy, self.base)
+
+    def test_reverse(self):
+        self.base.reverse()
+        self.lazy.reverse()
+        self.assertEqual(self.lazy, self.base)
+
+    def test_reversed(self):
+        self.assertEqual(list(reversed(self.lazy)), list(reversed(self.base)))
+
+    def test_sort(self):
+        self.base.sort()
+        self.assertNotEqual(self.lazy, self.base, 'Test data already sorted')
+        self.lazy.sort()
+        self.assertEqual(self.lazy, self.base)
+
+    def test_sorted(self):
+        self.assertEqual(sorted(self.lazy), sorted(self.base))
+
+    def test_getitem(self):
+        for idx in range(-len(self.base), len(self.base)):
+            self.assertEqual(self.lazy[idx], self.base[idx])
+
+    def test_setitem(self):
+        for idx in range(-len(self.base), len(self.base)):
+            self.base[idx] = idx + 1000
+            self.assertNotEqual(self.lazy, self.base)
+            self.lazy[idx] = idx + 1000
+            self.assertEqual(self.lazy, self.base)
+
+    def test_delitem(self):
+        del self.base[0]
+        self.assertNotEqual(self.lazy, self.base)
+        del self.lazy[0]
+        self.assertEqual(self.lazy, self.base)
+
+        del self.base[-2]
+        self.assertNotEqual(self.lazy, self.base)
+        del self.lazy[-2]
+        self.assertEqual(self.lazy, self.base)
+
+    def test_iter(self):
+        self.assertEqual(list(iter(self.lazy)), list(iter(self.base)))
+
+    def test_getslice(self):
+        for i in range(-len(self.base), len(self.base)):
+            for j in range(-len(self.base), len(self.base)):
+                for step in [-1, 1]:
+                    self.assertEqual(self.lazy[i:j:step], self.base[i:j:step])
+
+    def test_setslice(self):
+        for i in range(-len(self.base), len(self.base)):
+            for j in range(-len(self.base), len(self.base)):
+                for step in [-1, 1]:
+                    replacement = range(0, len(self.base[i:j:step]))
+                    self.base[i:j:step] = replacement
+                    self.lazy[i:j:step] = replacement
+                    self.assertEqual(self.lazy, self.base)
+
+    def test_delslice(self):
+        del self.base[0:1]
+        del self.lazy[0:1]
+        self.assertEqual(self.lazy, self.base)
+
+        del self.base[-1:1:-1]
+        del self.lazy[-1:1:-1]
+        self.assertEqual(self.lazy, self.base)
+
+
+class LazySetTestCase(unittest.TestCase):
+    initial_data = set([3, 2, 1])
+
+    def setUp(self):
+        self.base = set([3, 2, 1])
+        self.lazy = LazySet(iter(set(self.base)))
+
+    def test_unary_ops(self):
+        # These ops just need to work.
+        unary_ops = [str, repr]
+        try:
+            unary_ops.append(unicode)
+        except NameError:
+            pass  # unicode no longer exists in Python 3.
+
+        for op in unary_ops:
+            op(self.lazy)  # These ops just need to work.
+
+        # These ops should return identical values as a real set.
+        unary_ops = [len, bool, not_]
+
+        for op in unary_ops:
+            self.assertEqual(
+                op(self.lazy),
+                op(self.base), '%s(lazy) == %r' % (op, op(self.lazy)))
+
+    def test_binary_ops(self):
+        binary_ops = [eq, ge, gt, le, lt, ne, sub, and_, or_, xor]
+        try:
+            binary_ops.append(cmp)
+        except NameError:
+            pass  # cmp no longer exists in Python 3.
+
+        for op in binary_ops:
+            self.assertEqual(
+                op(self.lazy, self.lazy),
+                op(self.base, self.base), str(op))
+            self.assertEqual(
+                op(self.lazy, self.base),
+                op(self.base, self.base), str(op))
+            self.assertEqual(
+                op(self.base, self.lazy),
+                op(self.base, self.base), str(op))
+
+        # Contains
+        self.assertTrue(2 in self.lazy)
+        self.assertFalse(42 in self.lazy)
+
+    def test_iops(self):
+        try:
+            iops = [isub, iand, ior, ixor]
+        except NameError:
+            return  # Don't exist in older Python versions.
+        for op in iops:
+            # Mutating operators, so make fresh copies.
+            lazy = LazySet(self.base)
+            base = self.base.copy()
+            op(lazy, set([1]))
+            op(base, set([1]))
+            self.assertEqual(lazy, base, str(op))
+
+    def test_bool(self):
+        self.assertTrue(bool(self.lazy))
+        self.assertFalse(bool(LazySet()))
+        self.assertFalse(bool(LazySet(iter([]))))
+
+    def test_hash(self):
+        self.assertRaises(TypeError, hash, self.lazy)
+
+    def test_isinstance(self):
+        self.assertTrue(isinstance(self.lazy, set))
+
+    def test_callable(self):
+        try:
+            callable
+        except NameError:
+            return  # No longer exists with Python 3.
+        self.assertFalse(callable(self.lazy))
+
+    def test_add(self):
+        self.base.add('extra')
+        self.lazy.add('extra')
+        self.assertEqual(self.lazy, self.base)
+
+    def test_copy(self):
+        self.assertEqual(self.lazy.copy(), self.base)
+
+    def test_method_ops(self):
+        ops = [
+            'difference', 'intersection', 'isdisjoint',
+            'issubset', 'issuperset', 'symmetric_difference', 'union',
+            'difference_update', 'intersection_update',
+            'symmetric_difference_update', 'update']
+        for op in ops:
+            if not hasattr(set, op):
+                continue  # Not in this version of Python.
+            # Make a copy, as some of the ops are mutating.
+            lazy = LazySet(set(self.base))
+            base = set(self.base)
+            self.assertEqual(
+                getattr(lazy, op)(set([1])),
+                getattr(base, op)(set([1])), op)
+            self.assertEqual(lazy, base, op)
+
+    def test_discard(self):
+        self.base.discard(1)
+        self.assertNotEqual(self.lazy, self.base)
+        self.lazy.discard(1)
+        self.assertEqual(self.lazy, self.base)
+
+    def test_pop(self):
+        self.assertEqual(self.lazy.pop(), self.base.pop())
+        self.assertEqual(self.lazy, self.base)
+
+    def test_remove(self):
+        self.base.remove(2)
+        self.lazy.remove(2)
+        self.assertEqual(self.lazy, self.base)
+
+    def test_clear(self):
+        self.lazy.clear()
+        self.assertEqual(self.lazy, set())
+
+
+if __name__ == '__main__':
+    warnings.simplefilter("error")  # Warnings should be fatal in tests.
+    unittest.main()
diff --git a/src/pytz/tests/test_tzinfo.py b/src/pytz/tests/test_tzinfo.py
new file mode 100644
index 0000000..a16c870
--- /dev/null
+++ b/src/pytz/tests/test_tzinfo.py
@@ -0,0 +1,870 @@
+# -*- coding: ascii -*-
+
+import doctest
+import sys
+import os
+import os.path
+import unittest
+try:
+    import cPickle as pickle
+except ImportError:
+    import pickle
+from datetime import (
+    datetime,
+    timedelta
+)
+import warnings
+
+if __name__ == '__main__':
+    # Only munge path if invoked as a script. Testrunners should have setup
+    # the paths already
+    sys.path.insert(0, os.path.abspath(os.path.join(os.pardir, os.pardir)))
+
+import pytz  # noqa
+from pytz import reference  # noqa
+from pytz.tzfile import _byte_string  # noqa
+from pytz.tzinfo import DstTzInfo, StaticTzInfo  # noqa
+
+# I test for expected version to ensure the correct version of pytz is
+# actually being tested.
+EXPECTED_VERSION = '2021.3'
+EXPECTED_OLSON_VERSION = '2021c'
+
+fmt = '%Y-%m-%d %H:%M:%S %Z%z'
+
+NOTIME = timedelta(0)
+
+# GMT is a tzinfo.StaticTzInfo--the class we primarily want to test--while
+# UTC is reference implementation.  They both have the same timezone meaning.
+UTC = pytz.timezone('UTC')
+GMT = pytz.timezone('GMT')
+assert isinstance(GMT, StaticTzInfo), 'GMT is no longer a StaticTzInfo'
+
+
+def prettydt(dt):
+    """datetime as a string using a known format.
+
+    We don't use strftime as it doesn't handle years earlier than 1900
+    per http://bugs.python.org/issue1777412
+    """
+    if dt.utcoffset() >= timedelta(0):
+        offset = '+%s' % (dt.utcoffset(),)
+    else:
+        offset = '-%s' % (-1 * dt.utcoffset(),)
+    return '%04d-%02d-%02d %02d:%02d:%02d %s %s' % (
+        dt.year, dt.month, dt.day,
+        dt.hour, dt.minute, dt.second,
+        dt.tzname(), offset)
+
+
+if sys.version_info[0] > 2:
+    # Python 3.x doesn't have unicode(), making writing code
+    # for Python 2.3 and Python 3.x a pain.
+    unicode = str
+
+
+class BasicTest(unittest.TestCase):
+
+    def testVersion(self):
+        # Ensuring the correct version of pytz has been loaded
+        self.assertEqual(
+            EXPECTED_VERSION, pytz.__version__,
+            'Incorrect pytz version loaded. Import path is stuffed '
+            'or this test needs updating. (Wanted %s, got %s)'
+            % (EXPECTED_VERSION, pytz.__version__)
+        )
+
+        self.assertEqual(
+            EXPECTED_OLSON_VERSION, pytz.OLSON_VERSION,
+            'Incorrect pytz version loaded. Import path is stuffed '
+            'or this test needs updating. (Wanted %s, got %s)'
+            % (EXPECTED_OLSON_VERSION, pytz.OLSON_VERSION)
+        )
+
+    def testGMT(self):
+        now = datetime.now(tz=GMT)
+        self.assertTrue(now.utcoffset() == NOTIME)
+        self.assertTrue(now.dst() == NOTIME)
+        self.assertTrue(now.timetuple() == now.utctimetuple())
+        self.assertTrue(now == now.replace(tzinfo=UTC))
+
+    def testReferenceUTC(self):
+        now = datetime.now(tz=UTC)
+        self.assertTrue(now.utcoffset() == NOTIME)
+        self.assertTrue(now.dst() == NOTIME)
+        self.assertTrue(now.timetuple() == now.utctimetuple())
+
+    def testUnknownOffsets(self):
+        # This tzinfo behavior is required to make
+        # datetime.time.{utcoffset, dst, tzname} work as documented.
+
+        dst_tz = pytz.timezone('US/Eastern')
+
+        # This information is not known when we don't have a date,
+        # so return None per API.
+        self.assertTrue(dst_tz.utcoffset(None) is None)
+        self.assertTrue(dst_tz.dst(None) is None)
+        # We don't know the abbreviation, but this is still a valid
+        # tzname per the Python documentation.
+        self.assertEqual(dst_tz.tzname(None), 'US/Eastern')
+
+    def clearCache(self):
+        pytz._tzinfo_cache.clear()
+
+    def testUnicodeTimezone(self):
+        # We need to ensure that cold lookups work for both Unicode
+        # and traditional strings, and that the desired singleton is
+        # returned.
+        self.clearCache()
+        eastern = pytz.timezone(unicode('US/Eastern'))
+        self.assertTrue(eastern is pytz.timezone('US/Eastern'))
+
+        self.clearCache()
+        eastern = pytz.timezone('US/Eastern')
+        self.assertTrue(eastern is pytz.timezone(unicode('US/Eastern')))
+
+    def testStaticTzInfo(self):
+        # Ensure that static timezones are correctly detected,
+        # per lp:1602807
+        static = pytz.timezone('Etc/GMT-4')
+        self.assertTrue(isinstance(static, StaticTzInfo))
+
+
+class PicklingTest(unittest.TestCase):
+
+    def _roundtrip_tzinfo(self, tz):
+        p = pickle.dumps(tz)
+        unpickled_tz = pickle.loads(p)
+        self.assertTrue(tz is unpickled_tz, '%s did not roundtrip' % tz.zone)
+
+    def _roundtrip_datetime(self, dt):
+        # Ensure that the tzinfo attached to a datetime instance
+        # is identical to the one returned. This is important for
+        # DST timezones, as some state is stored in the tzinfo.
+        tz = dt.tzinfo
+        p = pickle.dumps(dt)
+        unpickled_dt = pickle.loads(p)
+        unpickled_tz = unpickled_dt.tzinfo
+        self.assertTrue(tz is unpickled_tz, '%s did not roundtrip' % tz.zone)
+
+    def testDst(self):
+        tz = pytz.timezone('Europe/Amsterdam')
+        dt = datetime(2004, 2, 1, 0, 0, 0)
+
+        for localized_tz in tz._tzinfos.values():
+            self._roundtrip_tzinfo(localized_tz)
+            self._roundtrip_datetime(dt.replace(tzinfo=localized_tz))
+
+    def testRoundtrip(self):
+        for zone in pytz.all_timezones:
+            tz = pytz.timezone(zone)
+            self._roundtrip_tzinfo(tz)
+
+    def testDatabaseFixes(self):
+        # Hack the pickle to make it refer to a timezone abbreviation
+        # that does not match anything. The unpickler should be able
+        # to repair this case
+        tz = pytz.timezone('Australia/Melbourne')
+        p = pickle.dumps(tz)
+        tzname = tz._tzname
+        hacked_p = p.replace(
+            _byte_string(tzname),
+            _byte_string('?' * len(tzname))
+        )
+        self.assertNotEqual(p, hacked_p)
+        unpickled_tz = pickle.loads(hacked_p)
+        self.assertTrue(tz is unpickled_tz)
+
+        # Simulate a database correction. In this case, the incorrect
+        # data will continue to be used.
+        p = pickle.dumps(tz)
+        new_utcoffset = tz._utcoffset.seconds + 42
+
+        # Python 3 introduced a new pickle protocol where numbers are stored in
+        # hexadecimal representation. Here we extract the pickle
+        # representation of the number for the current Python version.
+        #
+        # Test protocol 3 on Python 3 and protocol 0 on Python 2.
+        if sys.version_info >= (3,):
+            protocol = 3
+        else:
+            protocol = 0
+        old_pickle_pattern = pickle.dumps(tz._utcoffset.seconds, protocol)[3:-1]
+        new_pickle_pattern = pickle.dumps(new_utcoffset, protocol)[3:-1]
+        hacked_p = p.replace(old_pickle_pattern, new_pickle_pattern)
+
+        self.assertNotEqual(p, hacked_p)
+        unpickled_tz = pickle.loads(hacked_p)
+        self.assertEqual(unpickled_tz._utcoffset.seconds, new_utcoffset)
+        self.assertTrue(tz is not unpickled_tz)
+
+    def testOldPickles(self):
+        # Ensure that applications serializing pytz instances as pickles
+        # have no troubles upgrading to a new pytz release. These pickles
+        # where created with pytz2006j
+        east1 = pickle.loads(
+            _byte_string(
+                "cpytz\n_p\np1\n(S'US/Eastern'\np2\nI-18000\n"
+                "I0\nS'EST'\np3\ntRp4\n."
+            )
+        )
+        east2 = pytz.timezone('US/Eastern').localize(
+            datetime(2006, 1, 1)).tzinfo
+        self.assertTrue(east1 is east2)
+
+        # Confirm changes in name munging between 2006j and 2007c cause
+        # no problems.
+        pap1 = pickle.loads(_byte_string(
+            "cpytz\n_p\np1\n(S'America/Port_minus_au_minus_Prince'"
+            "\np2\nI-17340\nI0\nS'PPMT'\np3\ntRp4\n."))
+        pap2 = pytz.timezone('America/Port-au-Prince').localize(
+            datetime(1910, 1, 1)).tzinfo
+        self.assertTrue(pap1 is pap2)
+
+        gmt1 = pickle.loads(_byte_string(
+            "cpytz\n_p\np1\n(S'Etc/GMT_plus_10'\np2\ntRp3\n."))
+        gmt2 = pytz.timezone('Etc/GMT+10')
+        self.assertTrue(gmt1 is gmt2)
+
+
+class USEasternDSTStartTestCase(unittest.TestCase):
+    tzinfo = pytz.timezone('US/Eastern')
+
+    # 24 hours before DST changeover
+    transition_time = datetime(2002, 4, 7, 7, 0, 0, tzinfo=UTC)
+
+    # Increase for 'flexible' DST transitions due to 1 minute granularity
+    # of Python's datetime library
+    instant = timedelta(seconds=1)
+
+    # before transition
+    before = {
+        'tzname': 'EST',
+        'utcoffset': timedelta(hours=-5),
+        'dst': timedelta(hours=0),
+    }
+
+    # after transition
+    after = {
+        'tzname': 'EDT',
+        'utcoffset': timedelta(hours=-4),
+        'dst': timedelta(hours=1),
+    }
+
+    def _test_tzname(self, utc_dt, wanted):
+        tzname = wanted['tzname']
+        dt = utc_dt.astimezone(self.tzinfo)
+        self.assertEqual(
+            dt.tzname(), tzname,
+            'Expected %s as tzname for %s. Got %s' % (
+                tzname, str(utc_dt), dt.tzname()
+            )
+        )
+
+    def _test_utcoffset(self, utc_dt, wanted):
+        utcoffset = wanted['utcoffset']
+        dt = utc_dt.astimezone(self.tzinfo)
+        self.assertEqual(
+            dt.utcoffset(), wanted['utcoffset'],
+            'Expected %s as utcoffset for %s. Got %s' % (
+                utcoffset, utc_dt, dt.utcoffset()
+            )
+        )
+
+    def _test_dst(self, utc_dt, wanted):
+        dst = wanted['dst']
+        dt = utc_dt.astimezone(self.tzinfo)
+        self.assertEqual(
+            dt.dst(), dst,
+            'Expected %s as dst for %s. Got %s' % (dst, utc_dt, dt.dst())
+        )
+
+    def test_arithmetic(self):
+        utc_dt = self.transition_time
+
+        for days in range(-420, 720, 20):
+            delta = timedelta(days=days)
+
+            # Make sure we can get back where we started
+            dt = utc_dt.astimezone(self.tzinfo)
+            dt2 = dt + delta
+            dt2 = dt2 - delta
+            self.assertEqual(dt, dt2)
+
+            # Make sure arithmetic crossing DST boundaries ends
+            # up in the correct timezone after normalization
+            utc_plus_delta = (utc_dt + delta).astimezone(self.tzinfo)
+            local_plus_delta = self.tzinfo.normalize(dt + delta)
+            self.assertEqual(
+                prettydt(utc_plus_delta), prettydt(local_plus_delta),
+                'Incorrect result for delta==%d days.  Wanted %r. Got %r' % (
+                    days, prettydt(utc_plus_delta), prettydt(local_plus_delta),
+                )
+            )
+
+    def _test_all(self, utc_dt, wanted):
+        self._test_utcoffset(utc_dt, wanted)
+        self._test_tzname(utc_dt, wanted)
+        self._test_dst(utc_dt, wanted)
+
+    def testDayBefore(self):
+        self._test_all(
+            self.transition_time - timedelta(days=1), self.before
+        )
+
+    def testTwoHoursBefore(self):
+        self._test_all(
+            self.transition_time - timedelta(hours=2), self.before
+        )
+
+    def testHourBefore(self):
+        self._test_all(
+            self.transition_time - timedelta(hours=1), self.before
+        )
+
+    def testInstantBefore(self):
+        self._test_all(
+            self.transition_time - self.instant, self.before
+        )
+
+    def testTransition(self):
+        self._test_all(
+            self.transition_time, self.after
+        )
+
+    def testInstantAfter(self):
+        self._test_all(
+            self.transition_time + self.instant, self.after
+        )
+
+    def testHourAfter(self):
+        self._test_all(
+            self.transition_time + timedelta(hours=1), self.after
+        )
+
+    def testTwoHoursAfter(self):
+        self._test_all(
+            self.transition_time + timedelta(hours=1), self.after
+        )
+
+    def testDayAfter(self):
+        self._test_all(
+            self.transition_time + timedelta(days=1), self.after
+        )
+
+
+class USEasternDSTEndTestCase(USEasternDSTStartTestCase):
+    tzinfo = pytz.timezone('US/Eastern')
+    transition_time = datetime(2002, 10, 27, 6, 0, 0, tzinfo=UTC)
+    before = {
+        'tzname': 'EDT',
+        'utcoffset': timedelta(hours=-4),
+        'dst': timedelta(hours=1),
+    }
+    after = {
+        'tzname': 'EST',
+        'utcoffset': timedelta(hours=-5),
+        'dst': timedelta(hours=0),
+    }
+
+
+class USEasternEPTStartTestCase(USEasternDSTStartTestCase):
+    transition_time = datetime(1945, 8, 14, 23, 0, 0, tzinfo=UTC)
+    before = {
+        'tzname': 'EWT',
+        'utcoffset': timedelta(hours=-4),
+        'dst': timedelta(hours=1),
+    }
+    after = {
+        'tzname': 'EPT',
+        'utcoffset': timedelta(hours=-4),
+        'dst': timedelta(hours=1),
+    }
+
+
+class USEasternEPTEndTestCase(USEasternDSTStartTestCase):
+    transition_time = datetime(1945, 9, 30, 6, 0, 0, tzinfo=UTC)
+    before = {
+        'tzname': 'EPT',
+        'utcoffset': timedelta(hours=-4),
+        'dst': timedelta(hours=1),
+    }
+    after = {
+        'tzname': 'EST',
+        'utcoffset': timedelta(hours=-5),
+        'dst': timedelta(hours=0),
+    }
+
+
+class WarsawWMTEndTestCase(USEasternDSTStartTestCase):
+    # In 1915, Warsaw changed from Warsaw to Central European time.
+    # This involved the clocks being set backwards, causing a end-of-DST
+    # like situation without DST being involved.
+    tzinfo = pytz.timezone('Europe/Warsaw')
+    transition_time = datetime(1915, 8, 4, 22, 36, 0, tzinfo=UTC)
+    before = {
+        'tzname': 'WMT',
+        'utcoffset': timedelta(hours=1, minutes=24),
+        'dst': timedelta(0),
+    }
+    after = {
+        'tzname': 'CET',
+        'utcoffset': timedelta(hours=1),
+        'dst': timedelta(0),
+    }
+
+
+class VilniusWMTEndTestCase(USEasternDSTStartTestCase):
+    # At the end of 1916, Vilnius changed timezones putting its clock
+    # forward by 11 minutes 35 seconds. Neither timezone was in DST mode.
+    tzinfo = pytz.timezone('Europe/Vilnius')
+    instant = timedelta(seconds=31)
+    transition_time = datetime(1916, 12, 31, 22, 36, 00, tzinfo=UTC)
+    before = {
+        'tzname': 'WMT',
+        'utcoffset': timedelta(hours=1, minutes=24),
+        'dst': timedelta(0),
+    }
+    after = {
+        'tzname': 'KMT',
+        'utcoffset': timedelta(hours=1, minutes=36),  # Really 1:35:36
+        'dst': timedelta(0),
+    }
+
+
+class VilniusCESTStartTestCase(USEasternDSTStartTestCase):
+    # In 1941, Vilnius changed from MSG to CEST, switching to summer
+    # time while simultaneously reducing its UTC offset by two hours,
+    # causing the clocks to go backwards for this summer time
+    # switchover.
+    tzinfo = pytz.timezone('Europe/Vilnius')
+    transition_time = datetime(1941, 6, 23, 21, 00, 00, tzinfo=UTC)
+    before = {
+        'tzname': 'MSK',
+        'utcoffset': timedelta(hours=3),
+        'dst': timedelta(0),
+    }
+    after = {
+        'tzname': 'CEST',
+        'utcoffset': timedelta(hours=2),
+        'dst': timedelta(hours=1),
+    }
+
+
+class LondonHistoryStartTestCase(USEasternDSTStartTestCase):
+    # The first known timezone transition in London was in 1847 when
+    # clocks where synchronized to GMT. However, we currently only
+    # understand v1 format tzfile(5) files which does handle years
+    # this far in the past, so our earliest known transition is in
+    # 1916.
+    tzinfo = pytz.timezone('Europe/London')
+    # transition_time = datetime(1847, 12, 1, 1, 15, 00, tzinfo=UTC)
+    # before = {
+    #     'tzname': 'LMT',
+    #     'utcoffset': timedelta(minutes=-75),
+    #     'dst': timedelta(0),
+    #     }
+    # after = {
+    #     'tzname': 'GMT',
+    #     'utcoffset': timedelta(0),
+    #     'dst': timedelta(0),
+    #     }
+    transition_time = datetime(1916, 5, 21, 2, 00, 00, tzinfo=UTC)
+    before = {
+        'tzname': 'GMT',
+        'utcoffset': timedelta(0),
+        'dst': timedelta(0),
+    }
+    after = {
+        'tzname': 'BST',
+        'utcoffset': timedelta(hours=1),
+        'dst': timedelta(hours=1),
+    }
+
+
+class LondonHistoryEndTestCase(USEasternDSTStartTestCase):
+    # Timezone switchovers are projected into the future, even
+    # though no official statements exist or could be believed even
+    # if they did exist. We currently only check the last known
+    # transition in 2037, as we are still using v1 format tzfile(5)
+    # files.
+    tzinfo = pytz.timezone('Europe/London')
+    # transition_time = datetime(2499, 10, 25, 1, 0, 0, tzinfo=UTC)
+    transition_time = datetime(2037, 10, 25, 1, 0, 0, tzinfo=UTC)
+    before = {
+        'tzname': 'BST',
+        'utcoffset': timedelta(hours=1),
+        'dst': timedelta(hours=1),
+    }
+    after = {
+        'tzname': 'GMT',
+        'utcoffset': timedelta(0),
+        'dst': timedelta(0),
+    }
+
+
+class NoumeaHistoryStartTestCase(USEasternDSTStartTestCase):
+    # Noumea adopted a whole hour offset in 1912. Previously
+    # it was 11 hours, 5 minutes and 48 seconds off UTC. However,
+    # due to limitations of the Python datetime library, we need
+    # to round that to 11 hours 6 minutes.
+    tzinfo = pytz.timezone('Pacific/Noumea')
+    transition_time = datetime(1912, 1, 12, 12, 54, 12, tzinfo=UTC)
+    before = {
+        'tzname': 'LMT',
+        'utcoffset': timedelta(hours=11, minutes=6),
+        'dst': timedelta(0),
+    }
+    after = {
+        'tzname': '+11',  # pre-2017a, NCT
+        'utcoffset': timedelta(hours=11),
+        'dst': timedelta(0),
+    }
+
+
+class NoumeaDSTEndTestCase(USEasternDSTStartTestCase):
+    # Noumea dropped DST in 1997.
+    tzinfo = pytz.timezone('Pacific/Noumea')
+    transition_time = datetime(1997, 3, 1, 15, 00, 00, tzinfo=UTC)
+    before = {
+        'tzname': '+12',  # pre-2017a, NCST
+        'utcoffset': timedelta(hours=12),
+        'dst': timedelta(hours=1),
+    }
+    after = {
+        'tzname': '+11',  # pre-2017a, NCT
+        'utcoffset': timedelta(hours=11),
+        'dst': timedelta(0),
+    }
+
+
+class NoumeaNoMoreDSTTestCase(NoumeaDSTEndTestCase):
+    # Noumea dropped DST in 1997. Here we test that it stops occuring.
+    transition_time = (
+        NoumeaDSTEndTestCase.transition_time + timedelta(days=365 * 10))
+    before = NoumeaDSTEndTestCase.after
+    after = NoumeaDSTEndTestCase.after
+
+
+class TahitiTestCase(USEasternDSTStartTestCase):
+    # Tahiti has had a single transition in its history.
+    tzinfo = pytz.timezone('Pacific/Tahiti')
+    transition_time = datetime(1912, 10, 1, 9, 58, 16, tzinfo=UTC)
+    before = {
+        'tzname': 'LMT',
+        'utcoffset': timedelta(hours=-9, minutes=-58),
+        'dst': timedelta(0),
+    }
+    after = {
+        'tzname': '-10',  # pre-2017a, TAHT
+        'utcoffset': timedelta(hours=-10),
+        'dst': timedelta(0),
+    }
+
+
+class SamoaInternationalDateLineChange(USEasternDSTStartTestCase):
+    # At the end of 2011, Samoa will switch from being east of the
+    # international dateline to the west. There will be no Dec 30th
+    # 2011 and it will switch from UTC-10 to UTC+14.
+    tzinfo = pytz.timezone('Pacific/Apia')
+    transition_time = datetime(2011, 12, 30, 10, 0, 0, tzinfo=UTC)
+    before = {
+        'tzname': '-10',  # pre-2017a, SDT
+        'utcoffset': timedelta(hours=-10),
+        'dst': timedelta(hours=1),
+    }
+    after = {
+        'tzname': '+14',  # pre-2017a, WSDT
+        'utcoffset': timedelta(hours=14),
+        'dst': timedelta(hours=1),
+    }
+
+
+class ReferenceUSEasternDSTStartTestCase(USEasternDSTStartTestCase):
+    tzinfo = reference.Eastern
+
+    def test_arithmetic(self):
+        # Reference implementation cannot handle this
+        pass
+
+
+class ReferenceUSEasternDSTEndTestCase(USEasternDSTEndTestCase):
+    tzinfo = reference.Eastern
+
+    def testHourBefore(self):
+        # Python's datetime library has a bug, where the hour before
+        # a daylight saving transition is one hour out. For example,
+        # at the end of US/Eastern daylight saving time, 01:00 EST
+        # occurs twice (once at 05:00 UTC and once at 06:00 UTC),
+        # whereas the first should actually be 01:00 EDT.
+        # Note that this bug is by design - by accepting this ambiguity
+        # for one hour one hour per year, an is_dst flag on datetime.time
+        # became unnecessary.
+        self._test_all(self.transition_time - timedelta(hours=1), self.after)
+
+    def testInstantBefore(self):
+        self._test_all(self.transition_time - timedelta(seconds=1), self.after)
+
+    def test_arithmetic(self):
+        # Reference implementation cannot handle this
+        pass
+
+
+class LocalTestCase(unittest.TestCase):
+    def testLocalize(self):
+        loc_tz = pytz.timezone('Europe/Amsterdam')
+
+        loc_time = loc_tz.localize(datetime(1930, 5, 10, 0, 0, 0))
+        # Actually +00:19:32, but Python datetime rounds this
+        self.assertEqual(loc_time.strftime('%Z%z'), 'AMT+0020')
+
+        loc_time = loc_tz.localize(datetime(1930, 5, 20, 0, 0, 0))
+        # Actually +00:19:32, but Python datetime rounds this
+        self.assertEqual(loc_time.strftime('%Z%z'), 'NST+0120')
+
+        loc_time = loc_tz.localize(datetime(1940, 5, 10, 0, 0, 0))
+        # pre-2017a, abbreviation was NCT
+        self.assertEqual(loc_time.strftime('%Z%z'), '+0020+0020')
+
+        loc_time = loc_tz.localize(datetime(1940, 5, 20, 0, 0, 0))
+        self.assertEqual(loc_time.strftime('%Z%z'), 'CEST+0200')
+
+        loc_time = loc_tz.localize(datetime(2004, 2, 1, 0, 0, 0))
+        self.assertEqual(loc_time.strftime('%Z%z'), 'CET+0100')
+
+        loc_time = loc_tz.localize(datetime(2004, 4, 1, 0, 0, 0))
+        self.assertEqual(loc_time.strftime('%Z%z'), 'CEST+0200')
+
+        loc_time = loc_tz.localize(datetime(1943, 3, 29, 1, 59, 59))
+        self.assertEqual(loc_time.strftime('%Z%z'), 'CET+0100')
+
+        # Switch to US
+        loc_tz = pytz.timezone('US/Eastern')
+
+        # End of DST ambiguity check
+        loc_time = loc_tz.localize(datetime(1918, 10, 27, 1, 59, 59), is_dst=1)
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EDT-0400')
+
+        loc_time = loc_tz.localize(datetime(1918, 10, 27, 1, 59, 59), is_dst=0)
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EST-0500')
+
+        self.assertRaises(
+            pytz.AmbiguousTimeError,
+            loc_tz.localize, datetime(1918, 10, 27, 1, 59, 59), is_dst=None
+        )
+
+        # Start of DST non-existent times
+        loc_time = loc_tz.localize(datetime(1918, 3, 31, 2, 0, 0), is_dst=0)
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EST-0500')
+
+        loc_time = loc_tz.localize(datetime(1918, 3, 31, 2, 0, 0), is_dst=1)
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EDT-0400')
+
+        self.assertRaises(
+            pytz.NonExistentTimeError,
+            loc_tz.localize, datetime(1918, 3, 31, 2, 0, 0), is_dst=None
+        )
+
+        # Weird changes - war time and peace time both is_dst==True
+
+        loc_time = loc_tz.localize(datetime(1942, 2, 9, 3, 0, 0))
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EWT-0400')
+
+        loc_time = loc_tz.localize(datetime(1945, 8, 14, 19, 0, 0))
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EPT-0400')
+
+        loc_time = loc_tz.localize(datetime(1945, 9, 30, 1, 0, 0), is_dst=1)
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EPT-0400')
+
+        loc_time = loc_tz.localize(datetime(1945, 9, 30, 1, 0, 0), is_dst=0)
+        self.assertEqual(loc_time.strftime('%Z%z'), 'EST-0500')
+
+        # Weird changes - ambiguous time (end-of-DST like) but is_dst==False
+        for zonename, ambiguous_naive, expected in [
+                ('Europe/Warsaw', datetime(1915, 8, 4, 23, 59, 59),
+                 ['1915-08-04 23:59:59 WMT+0124',
+                  '1915-08-04 23:59:59 CET+0100']),
+                ('Europe/Moscow', datetime(2014, 10, 26, 1, 30),
+                 ['2014-10-26 01:30:00 MSK+0400',
+                  '2014-10-26 01:30:00 MSK+0300'])]:
+            loc_tz = pytz.timezone(zonename)
+            self.assertRaises(
+                pytz.AmbiguousTimeError,
+                loc_tz.localize, ambiguous_naive, is_dst=None
+            )
+            # Also test non-boolean is_dst in the weird case
+            for dst in [True, timedelta(1), False, timedelta(0)]:
+                loc_time = loc_tz.localize(ambiguous_naive, is_dst=dst)
+                self.assertEqual(loc_time.strftime(fmt), expected[not dst])
+
+    def testNormalize(self):
+        tz = pytz.timezone('US/Eastern')
+        dt = datetime(2004, 4, 4, 7, 0, 0, tzinfo=UTC).astimezone(tz)
+        dt2 = dt - timedelta(minutes=10)
+        self.assertEqual(
+            dt2.strftime('%Y-%m-%d %H:%M:%S %Z%z'),
+            '2004-04-04 02:50:00 EDT-0400'
+        )
+
+        dt2 = tz.normalize(dt2)
+        self.assertEqual(
+            dt2.strftime('%Y-%m-%d %H:%M:%S %Z%z'),
+            '2004-04-04 01:50:00 EST-0500'
+        )
+
+    def testPartialMinuteOffsets(self):
+        # utcoffset in Amsterdam was not a whole minute until 1937
+        # However, we fudge this by rounding them, as the Python
+        # datetime library
+        tz = pytz.timezone('Europe/Amsterdam')
+        utc_dt = datetime(1914, 1, 1, 13, 40, 28, tzinfo=UTC)  # correct
+        utc_dt = utc_dt.replace(second=0)  # But we need to fudge it
+        loc_dt = utc_dt.astimezone(tz)
+        self.assertEqual(
+            loc_dt.strftime('%Y-%m-%d %H:%M:%S %Z%z'),
+            '1914-01-01 14:00:00 AMT+0020'
+        )
+
+        # And get back...
+        utc_dt = loc_dt.astimezone(UTC)
+        self.assertEqual(
+            utc_dt.strftime('%Y-%m-%d %H:%M:%S %Z%z'),
+            '1914-01-01 13:40:00 UTC+0000'
+        )
+
+    def no_testCreateLocaltime(self):
+        # It would be nice if this worked, but it doesn't.
+        tz = pytz.timezone('Europe/Amsterdam')
+        dt = datetime(2004, 10, 31, 2, 0, 0, tzinfo=tz)
+        self.assertEqual(
+            dt.strftime(fmt),
+            '2004-10-31 02:00:00 CET+0100'
+        )
+
+
+class CommonTimezonesTestCase(unittest.TestCase):
+    def test_bratislava(self):
+        # Bratislava is the default timezone for Slovakia, but our
+        # heuristics where not adding it to common_timezones. Ideally,
+        # common_timezones should be populated from zone.tab at runtime,
+        # but I'm hesitant to pay the startup cost as loading the list
+        # on demand whilst remaining backwards compatible seems
+        # difficult.
+        self.assertTrue('Europe/Bratislava' in pytz.common_timezones)
+        self.assertTrue('Europe/Bratislava' in pytz.common_timezones_set)
+
+    def test_us_eastern(self):
+        self.assertTrue('US/Eastern' in pytz.common_timezones)
+        self.assertTrue('US/Eastern' in pytz.common_timezones_set)
+
+    def test_belfast(self):
+        # Belfast uses London time.
+        self.assertTrue('Europe/Belfast' in pytz.all_timezones_set)
+        self.assertFalse('Europe/Belfast' in pytz.common_timezones)
+        self.assertFalse('Europe/Belfast' in pytz.common_timezones_set)
+
+
+class ZoneCaseInsensitivityTestCase(unittest.TestCase):
+    def test_lower_case_timezone_constructor_arg(self):
+        for tz in pytz.all_timezones_set:
+            from_lower = pytz.timezone(tz.lower())
+            from_passed = pytz.timezone(tz)
+            self.assertEqual(from_lower,
+                             from_passed,
+                             "arg '%s' and arg '%s' produce different "
+                             "timezone objects" % (
+                                 from_lower, from_passed))
+
+
+class BaseTzInfoTestCase:
+    '''Ensure UTC, StaticTzInfo and DstTzInfo work consistently.
+
+    These tests are run for each type of tzinfo.
+    '''
+    tz = None  # override
+    tz_class = None  # override
+
+    def test_expectedclass(self):
+        self.assertTrue(isinstance(self.tz, self.tz_class))
+
+    def test_fromutc(self):
+        # naive datetime.
+        dt1 = datetime(2011, 10, 31)
+
+        # localized datetime, same timezone.
+        dt2 = self.tz.localize(dt1)
+
+        # Both should give the same results. Note that the standard
+        # Python tzinfo.fromutc() only supports the second.
+        for dt in [dt1, dt2]:
+            loc_dt = self.tz.fromutc(dt)
+            loc_dt2 = pytz.utc.localize(dt1).astimezone(self.tz)
+            self.assertEqual(loc_dt, loc_dt2)
+
+        # localized datetime, different timezone.
+        new_tz = pytz.timezone('Europe/Paris')
+        self.assertTrue(self.tz is not new_tz)
+        dt3 = new_tz.localize(dt1)
+        self.assertRaises(ValueError, self.tz.fromutc, dt3)
+
+    def test_normalize(self):
+        other_tz = pytz.timezone('Europe/Paris')
+        self.assertTrue(self.tz is not other_tz)
+
+        dt = datetime(2012, 3, 26, 12, 0)
+        other_dt = other_tz.localize(dt)
+
+        local_dt = self.tz.normalize(other_dt)
+
+        self.assertTrue(local_dt.tzinfo is not other_dt.tzinfo)
+        self.assertNotEqual(
+            local_dt.replace(tzinfo=None), other_dt.replace(tzinfo=None))
+
+    def test_astimezone(self):
+        other_tz = pytz.timezone('Europe/Paris')
+        self.assertTrue(self.tz is not other_tz)
+
+        dt = datetime(2012, 3, 26, 12, 0)
+        other_dt = other_tz.localize(dt)
+
+        local_dt = other_dt.astimezone(self.tz)
+
+        self.assertTrue(local_dt.tzinfo is not other_dt.tzinfo)
+        self.assertNotEqual(
+            local_dt.replace(tzinfo=None), other_dt.replace(tzinfo=None))
+
+
+class OptimizedUTCTestCase(unittest.TestCase, BaseTzInfoTestCase):
+    tz = pytz.utc
+    tz_class = tz.__class__
+
+
+class LegacyUTCTestCase(unittest.TestCase, BaseTzInfoTestCase):
+    # Deprecated timezone, but useful for comparison tests.
+    tz = pytz.timezone('Etc/UTC')
+    tz_class = StaticTzInfo
+
+
+class StaticTzInfoTestCase(unittest.TestCase, BaseTzInfoTestCase):
+    tz = pytz.timezone('GMT')
+    tz_class = StaticTzInfo
+
+
+class DstTzInfoTestCase(unittest.TestCase, BaseTzInfoTestCase):
+    tz = pytz.timezone('Australia/Melbourne')
+    tz_class = DstTzInfo
+
+
+def test_suite():
+    suite = unittest.TestSuite()
+    suite.addTest(doctest.DocTestSuite('pytz'))
+    suite.addTest(doctest.DocTestSuite('pytz.tzinfo'))
+    suite.addTest(doctest.DocTestSuite('pytz.exceptions'))
+    import test_tzinfo
+    suite.addTest(unittest.defaultTestLoader.loadTestsFromModule(test_tzinfo))
+    return suite
+
+
+if __name__ == '__main__':
+    warnings.simplefilter("error")  # Warnings should be fatal in tests.
+    unittest.main(defaultTest='test_suite')
diff --git a/src/pytz/tzfile.py b/src/pytz/tzfile.py
new file mode 100644
index 0000000..99e7448
--- /dev/null
+++ b/src/pytz/tzfile.py
@@ -0,0 +1,133 @@
+'''
+$Id: tzfile.py,v 1.8 2004/06/03 00:15:24 zenzen Exp $
+'''
+
+from datetime import datetime
+from struct import unpack, calcsize
+
+from pytz.tzinfo import StaticTzInfo, DstTzInfo, memorized_ttinfo
+from pytz.tzinfo import memorized_datetime, memorized_timedelta
+
+
+def _byte_string(s):
+    """Cast a string or byte string to an ASCII byte string."""
+    return s.encode('ASCII')
+
+_NULL = _byte_string('\0')
+
+
+def _std_string(s):
+    """Cast a string or byte string to an ASCII string."""
+    return str(s.decode('ASCII'))
+
+
+def build_tzinfo(zone, fp):
+    head_fmt = '>4s c 15x 6l'
+    head_size = calcsize(head_fmt)
+    (magic, format, ttisgmtcnt, ttisstdcnt, leapcnt, timecnt,
+        typecnt, charcnt) = unpack(head_fmt, fp.read(head_size))
+
+    # Make sure it is a tzfile(5) file
+    assert magic == _byte_string('TZif'), 'Got magic %s' % repr(magic)
+
+    # Read out the transition times, localtime indices and ttinfo structures.
+    data_fmt = '>%(timecnt)dl %(timecnt)dB %(ttinfo)s %(charcnt)ds' % dict(
+        timecnt=timecnt, ttinfo='lBB' * typecnt, charcnt=charcnt)
+    data_size = calcsize(data_fmt)
+    data = unpack(data_fmt, fp.read(data_size))
+
+    # make sure we unpacked the right number of values
+    assert len(data) == 2 * timecnt + 3 * typecnt + 1
+    transitions = [memorized_datetime(trans)
+                   for trans in data[:timecnt]]
+    lindexes = list(data[timecnt:2 * timecnt])
+    ttinfo_raw = data[2 * timecnt:-1]
+    tznames_raw = data[-1]
+    del data
+
+    # Process ttinfo into separate structs
+    ttinfo = []
+    tznames = {}
+    i = 0
+    while i < len(ttinfo_raw):
+        # have we looked up this timezone name yet?
+        tzname_offset = ttinfo_raw[i + 2]
+        if tzname_offset not in tznames:
+            nul = tznames_raw.find(_NULL, tzname_offset)
+            if nul < 0:
+                nul = len(tznames_raw)
+            tznames[tzname_offset] = _std_string(
+                tznames_raw[tzname_offset:nul])
+        ttinfo.append((ttinfo_raw[i],
+                       bool(ttinfo_raw[i + 1]),
+                       tznames[tzname_offset]))
+        i += 3
+
+    # Now build the timezone object
+    if len(ttinfo) == 1 or len(transitions) == 0:
+        ttinfo[0][0], ttinfo[0][2]
+        cls = type(zone, (StaticTzInfo,), dict(
+            zone=zone,
+            _utcoffset=memorized_timedelta(ttinfo[0][0]),
+            _tzname=ttinfo[0][2]))
+    else:
+        # Early dates use the first standard time ttinfo
+        i = 0
+        while ttinfo[i][1]:
+            i += 1
+        if ttinfo[i] == ttinfo[lindexes[0]]:
+            transitions[0] = datetime.min
+        else:
+            transitions.insert(0, datetime.min)
+            lindexes.insert(0, i)
+
+        # calculate transition info
+        transition_info = []
+        for i in range(len(transitions)):
+            inf = ttinfo[lindexes[i]]
+            utcoffset = inf[0]
+            if not inf[1]:
+                dst = 0
+            else:
+                for j in range(i - 1, -1, -1):
+                    prev_inf = ttinfo[lindexes[j]]
+                    if not prev_inf[1]:
+                        break
+                dst = inf[0] - prev_inf[0]  # dst offset
+
+                # Bad dst? Look further. DST > 24 hours happens when
+                # a timzone has moved across the international dateline.
+                if dst <= 0 or dst > 3600 * 3:
+                    for j in range(i + 1, len(transitions)):
+                        stdinf = ttinfo[lindexes[j]]
+                        if not stdinf[1]:
+                            dst = inf[0] - stdinf[0]
+                            if dst > 0:
+                                break  # Found a useful std time.
+
+            tzname = inf[2]
+
+            # Round utcoffset and dst to the nearest minute or the
+            # datetime library will complain. Conversions to these timezones
+            # might be up to plus or minus 30 seconds out, but it is
+            # the best we can do.
+            utcoffset = int((utcoffset + 30) // 60) * 60
+            dst = int((dst + 30) // 60) * 60
+            transition_info.append(memorized_ttinfo(utcoffset, dst, tzname))
+
+        cls = type(zone, (DstTzInfo,), dict(
+            zone=zone,
+            _utc_transition_times=transitions,
+            _transition_info=transition_info))
+
+    return cls()
+
+if __name__ == '__main__':
+    import os.path
+    from pprint import pprint
+    base = os.path.join(os.path.dirname(__file__), 'zoneinfo')
+    tz = build_tzinfo('Australia/Melbourne',
+                      open(os.path.join(base, 'Australia', 'Melbourne'), 'rb'))
+    tz = build_tzinfo('US/Eastern',
+                      open(os.path.join(base, 'US', 'Eastern'), 'rb'))
+    pprint(tz._utc_transition_times)
diff --git a/src/pytz/tzinfo.py b/src/pytz/tzinfo.py
new file mode 100644
index 0000000..725978d
--- /dev/null
+++ b/src/pytz/tzinfo.py
@@ -0,0 +1,577 @@
+'''Base classes and helpers for building zone specific tzinfo classes'''
+
+from datetime import datetime, timedelta, tzinfo
+from bisect import bisect_right
+try:
+    set
+except NameError:
+    from sets import Set as set
+
+import pytz
+from pytz.exceptions import AmbiguousTimeError, NonExistentTimeError
+
+__all__ = []
+
+_timedelta_cache = {}
+
+
+def memorized_timedelta(seconds):
+    '''Create only one instance of each distinct timedelta'''
+    try:
+        return _timedelta_cache[seconds]
+    except KeyError:
+        delta = timedelta(seconds=seconds)
+        _timedelta_cache[seconds] = delta
+        return delta
+
+_epoch = datetime.utcfromtimestamp(0)
+_datetime_cache = {0: _epoch}
+
+
+def memorized_datetime(seconds):
+    '''Create only one instance of each distinct datetime'''
+    try:
+        return _datetime_cache[seconds]
+    except KeyError:
+        # NB. We can't just do datetime.utcfromtimestamp(seconds) as this
+        # fails with negative values under Windows (Bug #90096)
+        dt = _epoch + timedelta(seconds=seconds)
+        _datetime_cache[seconds] = dt
+        return dt
+
+_ttinfo_cache = {}
+
+
+def memorized_ttinfo(*args):
+    '''Create only one instance of each distinct tuple'''
+    try:
+        return _ttinfo_cache[args]
+    except KeyError:
+        ttinfo = (
+            memorized_timedelta(args[0]),
+            memorized_timedelta(args[1]),
+            args[2]
+        )
+        _ttinfo_cache[args] = ttinfo
+        return ttinfo
+
+_notime = memorized_timedelta(0)
+
+
+def _to_seconds(td):
+    '''Convert a timedelta to seconds'''
+    return td.seconds + td.days * 24 * 60 * 60
+
+
+class BaseTzInfo(tzinfo):
+    # Overridden in subclass
+    _utcoffset = None
+    _tzname = None
+    zone = None
+
+    def __str__(self):
+        return self.zone
+
+
+class StaticTzInfo(BaseTzInfo):
+    '''A timezone that has a constant offset from UTC
+
+    These timezones are rare, as most locations have changed their
+    offset at some point in their history
+    '''
+    def fromutc(self, dt):
+        '''See datetime.tzinfo.fromutc'''
+        if dt.tzinfo is not None and dt.tzinfo is not self:
+            raise ValueError('fromutc: dt.tzinfo is not self')
+        return (dt + self._utcoffset).replace(tzinfo=self)
+
+    def utcoffset(self, dt, is_dst=None):
+        '''See datetime.tzinfo.utcoffset
+
+        is_dst is ignored for StaticTzInfo, and exists only to
+        retain compatibility with DstTzInfo.
+        '''
+        return self._utcoffset
+
+    def dst(self, dt, is_dst=None):
+        '''See datetime.tzinfo.dst
+
+        is_dst is ignored for StaticTzInfo, and exists only to
+        retain compatibility with DstTzInfo.
+        '''
+        return _notime
+
+    def tzname(self, dt, is_dst=None):
+        '''See datetime.tzinfo.tzname
+
+        is_dst is ignored for StaticTzInfo, and exists only to
+        retain compatibility with DstTzInfo.
+        '''
+        return self._tzname
+
+    def localize(self, dt, is_dst=False):
+        '''Convert naive time to local time'''
+        if dt.tzinfo is not None:
+            raise ValueError('Not naive datetime (tzinfo is already set)')
+        return dt.replace(tzinfo=self)
+
+    def normalize(self, dt, is_dst=False):
+        '''Correct the timezone information on the given datetime.
+
+        This is normally a no-op, as StaticTzInfo timezones never have
+        ambiguous cases to correct:
+
+        >>> from pytz import timezone
+        >>> gmt = timezone('GMT')
+        >>> isinstance(gmt, StaticTzInfo)
+        True
+        >>> dt = datetime(2011, 5, 8, 1, 2, 3, tzinfo=gmt)
+        >>> gmt.normalize(dt) is dt
+        True
+
+        The supported method of converting between timezones is to use
+        datetime.astimezone(). Currently normalize() also works:
+
+        >>> la = timezone('America/Los_Angeles')
+        >>> dt = la.localize(datetime(2011, 5, 7, 1, 2, 3))
+        >>> fmt = '%Y-%m-%d %H:%M:%S %Z (%z)'
+        >>> gmt.normalize(dt).strftime(fmt)
+        '2011-05-07 08:02:03 GMT (+0000)'
+        '''
+        if dt.tzinfo is self:
+            return dt
+        if dt.tzinfo is None:
+            raise ValueError('Naive time - no tzinfo set')
+        return dt.astimezone(self)
+
+    def __repr__(self):
+        return '<StaticTzInfo %r>' % (self.zone,)
+
+    def __reduce__(self):
+        # Special pickle to zone remains a singleton and to cope with
+        # database changes.
+        return pytz._p, (self.zone,)
+
+
+class DstTzInfo(BaseTzInfo):
+    '''A timezone that has a variable offset from UTC
+
+    The offset might change if daylight saving time comes into effect,
+    or at a point in history when the region decides to change their
+    timezone definition.
+    '''
+    # Overridden in subclass
+
+    # Sorted list of DST transition times, UTC
+    _utc_transition_times = None
+
+    # [(utcoffset, dstoffset, tzname)] corresponding to
+    # _utc_transition_times entries
+    _transition_info = None
+
+    zone = None
+
+    # Set in __init__
+
+    _tzinfos = None
+    _dst = None  # DST offset
+
+    def __init__(self, _inf=None, _tzinfos=None):
+        if _inf:
+            self._tzinfos = _tzinfos
+            self._utcoffset, self._dst, self._tzname = _inf
+        else:
+            _tzinfos = {}
+            self._tzinfos = _tzinfos
+            self._utcoffset, self._dst, self._tzname = (
+                self._transition_info[0])
+            _tzinfos[self._transition_info[0]] = self
+            for inf in self._transition_info[1:]:
+                if inf not in _tzinfos:
+                    _tzinfos[inf] = self.__class__(inf, _tzinfos)
+
+    def fromutc(self, dt):
+        '''See datetime.tzinfo.fromutc'''
+        if (dt.tzinfo is not None and
+                getattr(dt.tzinfo, '_tzinfos', None) is not self._tzinfos):
+            raise ValueError('fromutc: dt.tzinfo is not self')
+        dt = dt.replace(tzinfo=None)
+        idx = max(0, bisect_right(self._utc_transition_times, dt) - 1)
+        inf = self._transition_info[idx]
+        return (dt + inf[0]).replace(tzinfo=self._tzinfos[inf])
+
+    def normalize(self, dt):
+        '''Correct the timezone information on the given datetime
+
+        If date arithmetic crosses DST boundaries, the tzinfo
+        is not magically adjusted. This method normalizes the
+        tzinfo to the correct one.
+
+        To test, first we need to do some setup
+
+        >>> from pytz import timezone
+        >>> utc = timezone('UTC')
+        >>> eastern = timezone('US/Eastern')
+        >>> fmt = '%Y-%m-%d %H:%M:%S %Z (%z)'
+
+        We next create a datetime right on an end-of-DST transition point,
+        the instant when the wallclocks are wound back one hour.
+
+        >>> utc_dt = datetime(2002, 10, 27, 6, 0, 0, tzinfo=utc)
+        >>> loc_dt = utc_dt.astimezone(eastern)
+        >>> loc_dt.strftime(fmt)
+        '2002-10-27 01:00:00 EST (-0500)'
+
+        Now, if we subtract a few minutes from it, note that the timezone
+        information has not changed.
+
+        >>> before = loc_dt - timedelta(minutes=10)
+        >>> before.strftime(fmt)
+        '2002-10-27 00:50:00 EST (-0500)'
+
+        But we can fix that by calling the normalize method
+
+        >>> before = eastern.normalize(before)
+        >>> before.strftime(fmt)
+        '2002-10-27 01:50:00 EDT (-0400)'
+
+        The supported method of converting between timezones is to use
+        datetime.astimezone(). Currently, normalize() also works:
+
+        >>> th = timezone('Asia/Bangkok')
+        >>> am = timezone('Europe/Amsterdam')
+        >>> dt = th.localize(datetime(2011, 5, 7, 1, 2, 3))
+        >>> fmt = '%Y-%m-%d %H:%M:%S %Z (%z)'
+        >>> am.normalize(dt).strftime(fmt)
+        '2011-05-06 20:02:03 CEST (+0200)'
+        '''
+        if dt.tzinfo is None:
+            raise ValueError('Naive time - no tzinfo set')
+
+        # Convert dt in localtime to UTC
+        offset = dt.tzinfo._utcoffset
+        dt = dt.replace(tzinfo=None)
+        dt = dt - offset
+        # convert it back, and return it
+        return self.fromutc(dt)
+
+    def localize(self, dt, is_dst=False):
+        '''Convert naive time to local time.
+
+        This method should be used to construct localtimes, rather
+        than passing a tzinfo argument to a datetime constructor.
+
+        is_dst is used to determine the correct timezone in the ambigous
+        period at the end of daylight saving time.
+
+        >>> from pytz import timezone
+        >>> fmt = '%Y-%m-%d %H:%M:%S %Z (%z)'
+        >>> amdam = timezone('Europe/Amsterdam')
+        >>> dt  = datetime(2004, 10, 31, 2, 0, 0)
+        >>> loc_dt1 = amdam.localize(dt, is_dst=True)
+        >>> loc_dt2 = amdam.localize(dt, is_dst=False)
+        >>> loc_dt1.strftime(fmt)
+        '2004-10-31 02:00:00 CEST (+0200)'
+        >>> loc_dt2.strftime(fmt)
+        '2004-10-31 02:00:00 CET (+0100)'
+        >>> str(loc_dt2 - loc_dt1)
+        '1:00:00'
+
+        Use is_dst=None to raise an AmbiguousTimeError for ambiguous
+        times at the end of daylight saving time
+
+        >>> try:
+        ...     loc_dt1 = amdam.localize(dt, is_dst=None)
+        ... except AmbiguousTimeError:
+        ...     print('Ambiguous')
+        Ambiguous
+
+        is_dst defaults to False
+
+        >>> amdam.localize(dt) == amdam.localize(dt, False)
+        True
+
+        is_dst is also used to determine the correct timezone in the
+        wallclock times jumped over at the start of daylight saving time.
+
+        >>> pacific = timezone('US/Pacific')
+        >>> dt = datetime(2008, 3, 9, 2, 0, 0)
+        >>> ploc_dt1 = pacific.localize(dt, is_dst=True)
+        >>> ploc_dt2 = pacific.localize(dt, is_dst=False)
+        >>> ploc_dt1.strftime(fmt)
+        '2008-03-09 02:00:00 PDT (-0700)'
+        >>> ploc_dt2.strftime(fmt)
+        '2008-03-09 02:00:00 PST (-0800)'
+        >>> str(ploc_dt2 - ploc_dt1)
+        '1:00:00'
+
+        Use is_dst=None to raise a NonExistentTimeError for these skipped
+        times.
+
+        >>> try:
+        ...     loc_dt1 = pacific.localize(dt, is_dst=None)
+        ... except NonExistentTimeError:
+        ...     print('Non-existent')
+        Non-existent
+        '''
+        if dt.tzinfo is not None:
+            raise ValueError('Not naive datetime (tzinfo is already set)')
+
+        # Find the two best possibilities.
+        possible_loc_dt = set()
+        for delta in [timedelta(days=-1), timedelta(days=1)]:
+            loc_dt = dt + delta
+            idx = max(0, bisect_right(
+                self._utc_transition_times, loc_dt) - 1)
+            inf = self._transition_info[idx]
+            tzinfo = self._tzinfos[inf]
+            loc_dt = tzinfo.normalize(dt.replace(tzinfo=tzinfo))
+            if loc_dt.replace(tzinfo=None) == dt:
+                possible_loc_dt.add(loc_dt)
+
+        if len(possible_loc_dt) == 1:
+            return possible_loc_dt.pop()
+
+        # If there are no possibly correct timezones, we are attempting
+        # to convert a time that never happened - the time period jumped
+        # during the start-of-DST transition period.
+        if len(possible_loc_dt) == 0:
+            # If we refuse to guess, raise an exception.
+            if is_dst is None:
+                raise NonExistentTimeError(dt)
+
+            # If we are forcing the pre-DST side of the DST transition, we
+            # obtain the correct timezone by winding the clock forward a few
+            # hours.
+            elif is_dst:
+                return self.localize(
+                    dt + timedelta(hours=6), is_dst=True) - timedelta(hours=6)
+
+            # If we are forcing the post-DST side of the DST transition, we
+            # obtain the correct timezone by winding the clock back.
+            else:
+                return self.localize(
+                    dt - timedelta(hours=6),
+                    is_dst=False) + timedelta(hours=6)
+
+        # If we get this far, we have multiple possible timezones - this
+        # is an ambiguous case occuring during the end-of-DST transition.
+
+        # If told to be strict, raise an exception since we have an
+        # ambiguous case
+        if is_dst is None:
+            raise AmbiguousTimeError(dt)
+
+        # Filter out the possiblilities that don't match the requested
+        # is_dst
+        filtered_possible_loc_dt = [
+            p for p in possible_loc_dt if bool(p.tzinfo._dst) == is_dst
+        ]
+
+        # Hopefully we only have one possibility left. Return it.
+        if len(filtered_possible_loc_dt) == 1:
+            return filtered_possible_loc_dt[0]
+
+        if len(filtered_possible_loc_dt) == 0:
+            filtered_possible_loc_dt = list(possible_loc_dt)
+
+        # If we get this far, we have in a wierd timezone transition
+        # where the clocks have been wound back but is_dst is the same
+        # in both (eg. Europe/Warsaw 1915 when they switched to CET).
+        # At this point, we just have to guess unless we allow more
+        # hints to be passed in (such as the UTC offset or abbreviation),
+        # but that is just getting silly.
+        #
+        # Choose the earliest (by UTC) applicable timezone if is_dst=True
+        # Choose the latest (by UTC) applicable timezone if is_dst=False
+        # i.e., behave like end-of-DST transition
+        dates = {}  # utc -> local
+        for local_dt in filtered_possible_loc_dt:
+            utc_time = (
+                local_dt.replace(tzinfo=None) - local_dt.tzinfo._utcoffset)
+            assert utc_time not in dates
+            dates[utc_time] = local_dt
+        return dates[[min, max][not is_dst](dates)]
+
+    def utcoffset(self, dt, is_dst=None):
+        '''See datetime.tzinfo.utcoffset
+
+        The is_dst parameter may be used to remove ambiguity during DST
+        transitions.
+
+        >>> from pytz import timezone
+        >>> tz = timezone('America/St_Johns')
+        >>> ambiguous = datetime(2009, 10, 31, 23, 30)
+
+        >>> str(tz.utcoffset(ambiguous, is_dst=False))
+        '-1 day, 20:30:00'
+
+        >>> str(tz.utcoffset(ambiguous, is_dst=True))
+        '-1 day, 21:30:00'
+
+        >>> try:
+        ...     tz.utcoffset(ambiguous)
+        ... except AmbiguousTimeError:
+        ...     print('Ambiguous')
+        Ambiguous
+
+        '''
+        if dt is None:
+            return None
+        elif dt.tzinfo is not self:
+            dt = self.localize(dt, is_dst)
+            return dt.tzinfo._utcoffset
+        else:
+            return self._utcoffset
+
+    def dst(self, dt, is_dst=None):
+        '''See datetime.tzinfo.dst
+
+        The is_dst parameter may be used to remove ambiguity during DST
+        transitions.
+
+        >>> from pytz import timezone
+        >>> tz = timezone('America/St_Johns')
+
+        >>> normal = datetime(2009, 9, 1)
+
+        >>> str(tz.dst(normal))
+        '1:00:00'
+        >>> str(tz.dst(normal, is_dst=False))
+        '1:00:00'
+        >>> str(tz.dst(normal, is_dst=True))
+        '1:00:00'
+
+        >>> ambiguous = datetime(2009, 10, 31, 23, 30)
+
+        >>> str(tz.dst(ambiguous, is_dst=False))
+        '0:00:00'
+        >>> str(tz.dst(ambiguous, is_dst=True))
+        '1:00:00'
+        >>> try:
+        ...     tz.dst(ambiguous)
+        ... except AmbiguousTimeError:
+        ...     print('Ambiguous')
+        Ambiguous
+
+        '''
+        if dt is None:
+            return None
+        elif dt.tzinfo is not self:
+            dt = self.localize(dt, is_dst)
+            return dt.tzinfo._dst
+        else:
+            return self._dst
+
+    def tzname(self, dt, is_dst=None):
+        '''See datetime.tzinfo.tzname
+
+        The is_dst parameter may be used to remove ambiguity during DST
+        transitions.
+
+        >>> from pytz import timezone
+        >>> tz = timezone('America/St_Johns')
+
+        >>> normal = datetime(2009, 9, 1)
+
+        >>> tz.tzname(normal)
+        'NDT'
+        >>> tz.tzname(normal, is_dst=False)
+        'NDT'
+        >>> tz.tzname(normal, is_dst=True)
+        'NDT'
+
+        >>> ambiguous = datetime(2009, 10, 31, 23, 30)
+
+        >>> tz.tzname(ambiguous, is_dst=False)
+        'NST'
+        >>> tz.tzname(ambiguous, is_dst=True)
+        'NDT'
+        >>> try:
+        ...     tz.tzname(ambiguous)
+        ... except AmbiguousTimeError:
+        ...     print('Ambiguous')
+        Ambiguous
+        '''
+        if dt is None:
+            return self.zone
+        elif dt.tzinfo is not self:
+            dt = self.localize(dt, is_dst)
+            return dt.tzinfo._tzname
+        else:
+            return self._tzname
+
+    def __repr__(self):
+        if self._dst:
+            dst = 'DST'
+        else:
+            dst = 'STD'
+        if self._utcoffset > _notime:
+            return '<DstTzInfo %r %s+%s %s>' % (
+                self.zone, self._tzname, self._utcoffset, dst
+            )
+        else:
+            return '<DstTzInfo %r %s%s %s>' % (
+                self.zone, self._tzname, self._utcoffset, dst
+            )
+
+    def __reduce__(self):
+        # Special pickle to zone remains a singleton and to cope with
+        # database changes.
+        return pytz._p, (
+            self.zone,
+            _to_seconds(self._utcoffset),
+            _to_seconds(self._dst),
+            self._tzname
+        )
+
+
+def unpickler(zone, utcoffset=None, dstoffset=None, tzname=None):
+    """Factory function for unpickling pytz tzinfo instances.
+
+    This is shared for both StaticTzInfo and DstTzInfo instances, because
+    database changes could cause a zones implementation to switch between
+    these two base classes and we can't break pickles on a pytz version
+    upgrade.
+    """
+    # Raises a KeyError if zone no longer exists, which should never happen
+    # and would be a bug.
+    tz = pytz.timezone(zone)
+
+    # A StaticTzInfo - just return it
+    if utcoffset is None:
+        return tz
+
+    # This pickle was created from a DstTzInfo. We need to
+    # determine which of the list of tzinfo instances for this zone
+    # to use in order to restore the state of any datetime instances using
+    # it correctly.
+    utcoffset = memorized_timedelta(utcoffset)
+    dstoffset = memorized_timedelta(dstoffset)
+    try:
+        return tz._tzinfos[(utcoffset, dstoffset, tzname)]
+    except KeyError:
+        # The particular state requested in this timezone no longer exists.
+        # This indicates a corrupt pickle, or the timezone database has been
+        # corrected violently enough to make this particular
+        # (utcoffset,dstoffset) no longer exist in the zone, or the
+        # abbreviation has been changed.
+        pass
+
+    # See if we can find an entry differing only by tzname. Abbreviations
+    # get changed from the initial guess by the database maintainers to
+    # match reality when this information is discovered.
+    for localized_tz in tz._tzinfos.values():
+        if (localized_tz._utcoffset == utcoffset and
+                localized_tz._dst == dstoffset):
+            return localized_tz
+
+    # This (utcoffset, dstoffset) information has been removed from the
+    # zone. Add it back. This might occur when the database maintainers have
+    # corrected incorrect information. datetime instances using this
+    # incorrect information will continue to do so, exactly as they were
+    # before being pickled. This is purely an overly paranoid safety net - I
+    # doubt this will ever been needed in real life.
+    inf = (utcoffset, dstoffset, tzname)
+    tz._tzinfos[inf] = tz.__class__(inf, tz._tzinfos)
+    return tz._tzinfos[inf]
diff --git a/src/pytz/zoneinfo b/src/pytz/zoneinfo
new file mode 120000
index 0000000..f169537
--- /dev/null
+++ b/src/pytz/zoneinfo
@@ -0,0 +1 @@
+../../build/etc/zoneinfo
+\ No newline at end of file
diff --git a/src/setup.cfg b/src/setup.cfg
new file mode 100644
index 0000000..d266b39
--- /dev/null
+++ b/src/setup.cfg
@@ -0,0 +1,5 @@
+[metadata]
+license_file = LICENSE.txt
+
+[flake8]
+max-line-length = 120
diff --git a/src/setup.py b/src/setup.py
new file mode 100644
index 0000000..fcf850c
--- /dev/null
+++ b/src/setup.py
@@ -0,0 +1,68 @@
+'''
+pytz setup script
+'''
+
+import pytz
+import os
+import os.path
+
+try:
+    from setuptools import setup
+except ImportError:
+    from distutils.core import setup
+
+me = 'Stuart Bishop'
+memail = 'stuart@stuartbishop.net'
+packages = ['pytz']
+resources = ['zone.tab', 'locales/pytz.pot']
+for dirpath, dirnames, filenames in os.walk(os.path.join('pytz', 'zoneinfo')):
+    # remove the 'pytz' part of the path
+    basepath = dirpath.split(os.path.sep, 1)[1]
+    resources.extend([os.path.join(basepath, filename) for filename in filenames])
+package_data = {'pytz': resources}
+
+assert len(resources) > 10, 'zoneinfo files not found!'
+
+setup(
+    name='pytz',
+    version=pytz.VERSION,
+    zip_safe=True,
+    description='World timezone definitions, modern and historical',
+    long_description=open('README.rst', 'r').read(),
+    author=me,
+    author_email=memail,
+    maintainer=me,
+    maintainer_email=memail,
+    url='http://pythonhosted.org/pytz',
+    license='MIT',
+    keywords=['timezone', 'tzinfo', 'datetime', 'olson', 'time'],
+    packages=packages,
+    package_data=package_data,
+    download_url='https://pypi.org/project/pytz/',
+    platforms=['Independent'],
+    classifiers=[
+        'Development Status :: 6 - Mature',
+        'Intended Audience :: Developers',
+        'License :: OSI Approved :: MIT License',
+        'Natural Language :: English',
+        'Operating System :: OS Independent',
+        'Programming Language :: Python',
+        'Programming Language :: Python :: 2',
+        'Programming Language :: Python :: 2.4',
+        'Programming Language :: Python :: 2.5',
+        'Programming Language :: Python :: 2.6',
+        'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.1',
+        'Programming Language :: Python :: 3.2',
+        'Programming Language :: Python :: 3.3',
+        'Programming Language :: Python :: 3.4',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Topic :: Software Development :: Libraries :: Python Modules',
+    ],
+)
diff --git a/test_zdump.py b/test_zdump.py
new file mode 100644
index 0000000..3baedfc
--- /dev/null
+++ b/test_zdump.py
@@ -0,0 +1,138 @@
+#!/usr/bin/python2.7
+
+import os.path
+import sys
+sys.path.insert(0, os.path.join('build', 'dist'))
+
+from datetime import datetime, timedelta
+import re
+from time import strptime
+import unittest
+import pytz
+
+
+class ZdumpTestCase(unittest.TestCase):
+    def utc_to_local_check(self, zone, utc_dt, loc_dt, loc_tzname, is_dst):
+        loc_tz = pytz.timezone(zone)
+        self.failUnlessEqual(
+            utc_dt.astimezone(loc_tz).replace(tzinfo=None),
+            loc_dt.replace(tzinfo=None))
+
+    def local_to_utc_check(self, zone, utc_dt, loc_dt, loc_tzname, is_dst):
+        self.failUnlessEqual(
+            loc_dt.astimezone(pytz.utc).replace(tzinfo=None),
+            utc_dt.replace(tzinfo=None))
+
+
+def test_suite():
+    testcases = []
+    raw_data = open(
+        os.path.join(os.path.dirname(__file__), 'zdump.out'), 'r').readlines()
+    last_zone = None
+    test_class = None
+    zdump_line_re = re.compile(r'''(?x)
+        ^([^\s]+) \s+ (.+) \s UT \s+ = \s+ (.+) \s ([^\s]+) \s+
+                               isdst=(0|1) \s+ gmtoff=[\-\d]+ \s*$
+        ''')
+    for i in range(0, len(raw_data)):
+        line = raw_data[i]
+        m = zdump_line_re.search(line)
+        if m is None:
+            raise RuntimeError('Dud line %r' % (line,))
+        zone, utc_string, loc_string, tzname, is_dst = m.groups()
+        is_dst = bool(int(is_dst))
+
+        if zone != last_zone:
+            classname = zone.replace(
+                '+', '_plus_').replace('-', '_minus_').replace('/', '_')
+            test_class = type(classname, (ZdumpTestCase,), {})
+            testcases.append(test_class)
+            last_zone = zone
+            skip_next_local = False
+
+        utc_dt = datetime(
+            *strptime(utc_string, '%a %b %d %H:%M:%S %Y')[:6])
+        loc_dt = datetime(
+            *strptime(loc_string, '%a %b %d %H:%M:%S %Y')[:6])
+
+        def round_dt(loc_dt, utc_dt):
+            # Urgh - utcoffset() and dst() have to be rounded to the nearest
+            # minute, so we need to break our tests to match this limitation
+            real_offset = loc_dt - utc_dt
+            secs = real_offset.seconds + real_offset.days * 86400
+            fake_offset = timedelta(seconds=int((secs + 30) // 60) * 60)
+            return utc_dt + fake_offset
+
+        loc_dt = round_dt(loc_dt, utc_dt)
+
+        # If the naive time on the next line is less than on this
+        # line, and we aren't seeing an end-of-dst transition, then
+        # we can't do our local->utc tests for either this nor the
+        # next line since we are in an ambiguous time period (ie.
+        # we have wound back the clock but don't have differing
+        # is_dst flags to resolve the ambiguity)
+        skip_local = skip_next_local
+        skip_next_local = False
+        try:
+            m = zdump_line_re.match(raw_data[i + 1])
+        except IndexError:
+            m = None
+        if m is not None:
+            (next_zone, next_utc_string, next_loc_string,
+                next_tzname, next_is_dst) = m.groups()
+            next_is_dst = bool(int(next_is_dst))
+            if next_zone == zone and next_is_dst == is_dst:
+                next_utc_dt = datetime(
+                    *strptime(next_utc_string, '%a %b %d %H:%M:%S %Y')[:6])
+                next_loc_dt = round_dt(
+                    datetime(*strptime(
+                        next_loc_string, '%a %b %d %H:%M:%S %Y')[:6]),
+                    next_utc_dt)
+                if next_loc_dt <= loc_dt:
+                    skip_local = True
+                    skip_next_local = True
+
+        loc_tz = pytz.timezone(zone)
+        loc_dt = loc_tz.localize(loc_dt, is_dst)
+
+        utc_dt = pytz.utc.localize(utc_dt)
+
+        test_name = 'test_utc_to_local_%04d_%02d_%02d_%02d_%02d_%02d' % (
+            utc_dt.year, utc_dt.month, utc_dt.day,
+            utc_dt.hour, utc_dt.minute, utc_dt.second)
+
+        def test_utc_to_local(
+                self, zone=zone, utc_dt=utc_dt, loc_dt=loc_dt,
+                tzname=tzname, is_dst=is_dst):
+            self.utc_to_local_check(zone, utc_dt, loc_dt, tzname, is_dst)
+        test_utc_to_local.__name__ = test_name
+        setattr(test_class, test_name, test_utc_to_local)
+
+        if not skip_local:
+            test_name = 'test_local_to_utc_%04d_%02d_%02d_%02d_%02d_%02d' % (
+                loc_dt.year, loc_dt.month, loc_dt.day,
+                loc_dt.hour, loc_dt.minute, loc_dt.second)
+            if is_dst:
+                test_name += '_dst'
+            else:
+                test_name += '_nodst'
+
+            def test_local_to_utc(
+                    self, zone=zone, utc_dt=utc_dt, loc_dt=loc_dt,
+                    tzname=tzname, is_dst=is_dst):
+                self.local_to_utc_check(zone, utc_dt, loc_dt, tzname, is_dst)
+            test_local_to_utc.__name__ = test_name
+            setattr(test_class, test_name, test_local_to_utc)
+
+    classname = zone.replace(
+        '+', '_plus_').replace('-', '_minus_').replace('/', '_')
+    test_class = type(classname, (ZdumpTestCase,), {})
+    testcases.append(test_class)
+
+    suite = unittest.TestSuite()
+    while testcases:
+        suite.addTest(unittest.makeSuite(testcases.pop()))
+    return suite
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='test_suite')
diff --git a/tz/.gitignore b/tz/.gitignore
new file mode 100644
index 0000000..cf3b825
--- /dev/null
+++ b/tz/.gitignore
@@ -0,0 +1,26 @@
+# Files intentionally not tracked by Git.
+# This file is in the public domain.
+*.a
+*.asc
+*.diff
+*.i
+*.o
+*.orig
+*.patch
+*.rej
+*.tar
+*.tar.*
+*.txt
+*.tzs
+*.zi
+*~
+ChangeLog
+check_*
+date
+leapseconds
+tzselect
+version
+version.h
+yearistype
+zdump
+zic
diff --git a/CONTRIBUTING b/tz/CONTRIBUTING
index 4c0f56a..4c0f56a 100644
--- a/CONTRIBUTING
+++ b/tz/CONTRIBUTING
diff --git a/LICENSE b/tz/LICENSE
index 8ba4399..8ba4399 100644
--- a/LICENSE
+++ b/tz/LICENSE
diff --git a/tz/Makefile b/tz/Makefile
new file mode 100644
index 0000000..a9a989e
--- /dev/null
+++ b/tz/Makefile
@@ -0,0 +1,1146 @@
+# Make and install tzdb code and data.
+
+# This file is in the public domain, so clarified as of
+# 2009-05-17 by Arthur David Olson.
+
+# Package name for the code distribution.
+PACKAGE=	tzcode
+
+# Version number for the distribution, overridden in the 'tarballs' rule below.
+VERSION=	unknown
+
+# Email address for bug reports.
+BUGEMAIL=	tz@iana.org
+
+# DATAFORM selects the data format.
+# Available formats represent essentially the same data, albeit
+# possibly with minor discrepancies that users are not likely to notice.
+# To get new features and the best data right away, use:
+#	DATAFORM=	vanguard
+# To wait a while before using new features, to give downstream users
+# time to upgrade zic (the default), use:
+#	DATAFORM=	main
+# To wait even longer for new features, use:
+#	DATAFORM=	rearguard
+# Rearguard users might also want "ZFLAGS = -b fat"; see below.
+DATAFORM=		main
+
+# Change the line below for your timezone (after finding the one you want in
+# one of the $(TDATA) source files, or adding it to a source file).
+# Alternatively, if you discover you've got the wrong timezone, you can just
+# 'zic -l -' to remove it, or 'zic -l rightzone' to change it.
+# Use the command
+#	make zonenames
+# to get a list of the values you can use for LOCALTIME.
+
+LOCALTIME=	GMT
+
+# The POSIXRULES macro controls interpretation of nonstandard and obsolete
+# POSIX-like TZ settings like TZ='EET-2EEST' that lack DST transition rules.
+# Such a setting uses the rules in a template file to determine
+# "spring forward" and "fall back" days and times; the environment
+# variable itself specifies UT offsets of standard and daylight saving time.
+#
+# If POSIXRULES is '-', no template is installed; this is the default.
+#
+# Any other value for POSIXRULES is obsolete and should not be relied on, as:
+# * It does not work correctly in popular implementations such as GNU/Linux.
+# * It does not work even in tzcode, except for historical timestamps
+#   that precede the last explicit transition in the POSIXRULES file.
+#   Hence it typically does not work for current and future timestamps.
+# In short, software should avoid ruleless settings like TZ='EET-2EEST'
+# and so should not depend on the value of POSIXRULES.
+#
+# If, despite the above, you want a template for handling these settings,
+# you can change the line below (after finding the timezone you want in the
+# one of the $(TDATA) source files, or adding it to a source file).
+# Alternatively, if you discover you've got the wrong timezone, you can just
+# 'zic -p -' to remove it, or 'zic -p rightzone' to change it.
+# Use the command
+#	make zonenames
+# to get a list of the values you can use for POSIXRULES.
+
+POSIXRULES=	-
+
+# Also see TZDEFRULESTRING below, which takes effect only
+# if the time zone files cannot be accessed.
+
+
+# Installation locations.
+#
+# The defaults are suitable for Debian, except that if REDO is
+# posix_right or right_posix then files that Debian puts under
+# /usr/share/zoneinfo/posix and /usr/share/zoneinfo/right are instead
+# put under /usr/share/zoneinfo-posix and /usr/share/zoneinfo-leaps,
+# respectively.  Problems with the Debian approach are discussed in
+# the commentary for the right_posix rule (below).
+
+# Destination directory, which can be used for staging.
+# 'make DESTDIR=/stage install' installs under /stage (e.g., to
+# /stage/etc/localtime instead of to /etc/localtime).  Files under
+# /stage are not intended to work as-is, but can be copied by hand to
+# the root directory later.  If DESTDIR is empty, 'make install' does
+# not stage, but installs directly into production locations.
+DESTDIR =
+
+# Everything is installed into subdirectories of TOPDIR, and used there.
+# TOPDIR should be empty (meaning the root directory),
+# or a directory name that does not end in "/".
+# TOPDIR should be empty or an absolute name unless you're just testing.
+TOPDIR =
+
+# The default local timezone is taken from the file TZDEFAULT.
+TZDEFAULT = $(TOPDIR)/etc/localtime
+
+# The subdirectory containing installed program and data files, and
+# likewise for installed files that can be shared among architectures.
+# These should be relative file names.
+USRDIR = usr
+USRSHAREDIR = $(USRDIR)/share
+
+# "Compiled" timezone information is placed in the "TZDIR" directory
+# (and subdirectories).
+# TZDIR_BASENAME should not contain "/" and should not be ".", ".." or empty.
+TZDIR_BASENAME=	zoneinfo
+TZDIR = $(TOPDIR)/$(USRSHAREDIR)/$(TZDIR_BASENAME)
+
+# The "tzselect" and (if you do "make INSTALL") "date" commands go in:
+BINDIR = $(TOPDIR)/$(USRDIR)/bin
+
+# The "zdump" command goes in:
+ZDUMPDIR = $(BINDIR)
+
+# The "zic" command goes in:
+ZICDIR = $(TOPDIR)/$(USRDIR)/sbin
+
+# Manual pages go in subdirectories of. . .
+MANDIR = $(TOPDIR)/$(USRSHAREDIR)/man
+
+# Library functions are put in an archive in LIBDIR.
+LIBDIR = $(TOPDIR)/$(USRDIR)/lib
+
+
+# Types to try, as an alternative to time_t.
+TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL)
+TIME_T_ALTERNATIVES_HEAD = int_least64_t
+TIME_T_ALTERNATIVES_TAIL = int_least32_t uint_least32_t uint_least64_t
+
+# What kind of TZif data files to generate.  (TZif is the binary time
+# zone data format that zic generates; see Internet RFC 8536.)
+# If you want only POSIX time, with time values interpreted as
+# seconds since the epoch (not counting leap seconds), use
+#	REDO=		posix_only
+# below.  If you want only "right" time, with values interpreted
+# as seconds since the epoch (counting leap seconds), use
+#	REDO=		right_only
+# below.  If you want both sets of data available, with leap seconds not
+# counted normally, use
+#	REDO=		posix_right
+# below.  If you want both sets of data available, with leap seconds counted
+# normally, use
+#	REDO=		right_posix
+# below.  POSIX mandates that leap seconds not be counted; for compatibility
+# with it, use "posix_only" or "posix_right".  Use POSIX time on systems with
+# leap smearing; this can work better than unsmeared "right" time with
+# applications that are not leap second aware, and is closer to unsmeared
+# "right" time than unsmeared POSIX time is (e.g., 0.5 vs 1.0 s max error).
+
+REDO=		posix_right
+
+# Whether to put an "Expires" line in the leapseconds file.
+# Use EXPIRES_LINE=1 to put the line in, 0 to omit it.
+# The EXPIRES_LINE value matters only if REDO's value contains "right".
+# If you change EXPIRES_LINE, remove the leapseconds file before running "make".
+# zic's support for the Expires line was introduced in tzdb 2020a,
+# and was modified in tzdb 2021b to generate version 4 TZif files.
+# EXPIRES_LINE defaults to 0 for now so that the leapseconds file
+# can be given to pre-2020a zic implementations and so that TZif files
+# built by newer zic implementations can be read by pre-2021b libraries.
+EXPIRES_LINE=	0
+
+# To install data in text form that has all the information of the TZif data,
+# (optionally incorporating leap second information), use
+#	TZDATA_TEXT=	tzdata.zi leapseconds
+# To install text data without leap second information (e.g., because
+# REDO='posix_only'), use
+#	TZDATA_TEXT=	tzdata.zi
+# To avoid installing text data, use
+#	TZDATA_TEXT=
+
+TZDATA_TEXT=	leapseconds tzdata.zi
+
+# For backward-compatibility links for old zone names, use
+#	BACKWARD=	backward
+# To omit these links, use
+#	BACKWARD=
+
+BACKWARD=	backward
+
+# If you want out-of-scope and often-wrong data from the file 'backzone', use
+#	PACKRATDATA=	backzone
+# To omit this data, use
+#	PACKRATDATA=
+
+PACKRATDATA=
+
+# The name of a locale using the UTF-8 encoding, used during self-tests.
+# The tests are skipped if the name does not appear to work on this system.
+
+UTF8_LOCALE=	en_US.utf8
+
+# Non-default libraries needed to link.
+LDLIBS=
+
+# Add the following to the end of the "CFLAGS=" line as needed to override
+# defaults specified in the source code.  "-DFOO" is equivalent to "-DFOO=1".
+#  -DDEPRECATE_TWO_DIGIT_YEARS for optional runtime warnings about strftime
+#	formats that generate only the last two digits of year numbers
+#  -DEPOCH_LOCAL if the 'time' function returns local time not UT
+#  -DEPOCH_OFFSET=N if the 'time' function returns a value N greater
+#	than what POSIX specifies, assuming local time is UT.
+#	For example, N is 252460800 on AmigaOS.
+#  -DHAVE_DECL_ASCTIME_R=0 if <time.h> does not declare asctime_r
+#  -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ'
+#  -DHAVE_DIRECT_H if mkdir needs <direct.h> (MS-Windows)
+#  -DHAVE_GENERIC=0 if _Generic does not work
+#  -DHAVE_GETTEXT if 'gettext' works (e.g., GNU/Linux, FreeBSD, Solaris)
+#  -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares
+#	ctime_r and asctime_r incompatibly with the POSIX standard
+#	(Solaris when _POSIX_PTHREAD_SEMANTICS is not defined).
+#  -DHAVE_INTTYPES_H if you have a non-C99 compiler with <inttypes.h>
+#  -DHAVE_LINK=0 if your system lacks a link function
+#  -DHAVE_LOCALTIME_R=0 if your system lacks a localtime_r function
+#  -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz
+#	localtime_rz can make zdump significantly faster, but is nonstandard.
+#  -DHAVE_MALLOC_ERRNO=0 if malloc etc. do not set errno on failure.
+#  -DHAVE_POSIX_DECLS=0 if your system's include files do not declare
+#	functions like 'link' or variables like 'tzname' required by POSIX
+#  -DHAVE_SNPRINTF=0 if your system lacks the snprintf function
+#  -DHAVE_STDBOOL_H if you have a non-C99 compiler with <stdbool.h>
+#  -DHAVE_STDINT_H if you have a non-C99 compiler with <stdint.h>
+#  -DHAVE_STRFTIME_L if <time.h> declares locale_t and strftime_l
+#  -DHAVE_STRDUP=0 if your system lacks the strdup function
+#  -DHAVE_STRTOLL=0 if your system lacks the strtoll function
+#  -DHAVE_SYMLINK=0 if your system lacks the symlink function
+#  -DHAVE_SYS_STAT_H=0 if your compiler lacks a <sys/stat.h>
+#  -DHAVE_TZSET=0 if your system lacks a tzset function
+#  -DHAVE_UNISTD_H=0 if your compiler lacks a <unistd.h>
+#  -Dlocale_t=XXX if your system uses XXX instead of locale_t
+#  -DRESERVE_STD_EXT_IDS if your platform reserves standard identifiers
+#	with external linkage, e.g., applications cannot define 'localtime'.
+#  -Dssize_t=long on hosts like MS-Windows that lack ssize_t
+#  -DSUPPRESS_TZDIR to not prepend TZDIR to file names; this has
+#	security implications and is not recommended for general use
+#  -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires;
+#	not needed by the main-program tz code, which is single-threaded.
+#	Append other compiler flags as needed, e.g., -pthread on GNU/Linux.
+#  -Dtime_tz=\"T\" to use T as the time_t type, rather than the system time_t
+#	This is intended for internal use only; it mangles external names.
+#  -DTZ_DOMAIN=\"foo\" to use "foo" for gettext domain name; default is "tz"
+#  -DTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory;
+#	the default is system-supplied, typically "/usr/lib/locale"
+#  -DTZDEFRULESTRING=\",date/time,date/time\" to default to the specified
+#	DST transitions if the time zone files cannot be accessed
+#  -DUNINIT_TRAP if reading uninitialized storage can cause problems
+#	other than simply getting garbage data
+#  -DUSE_LTZ=0 to build zdump with the system time zone library
+#	Also set TZDOBJS=zdump.o and CHECK_TIME_T_ALTERNATIVES= below.
+#  -DZIC_BLOAT_DEFAULT=\"fat\" to default zic's -b option to "fat", and
+#	similarly for "slim".  Fat TZif files work around incompatibilities
+#	and bugs in some TZif readers, notably readers that mishandle 64-bit
+#	data in TZif files.  Slim TZif files are more efficient and do not
+#	work around these incompatibilities and bugs.  If not given, the
+#	default is "slim".
+#  -DZIC_MAX_ABBR_LEN_WO_WARN=3
+#	(or some other number) to set the maximum time zone abbreviation length
+#	that zic will accept without a warning (the default is 6)
+#  $(GCC_DEBUG_FLAGS) if you are using recent GCC and want lots of checking
+# Select instrumentation via "make GCC_INSTRUMENT='whatever'".
+GCC_INSTRUMENT = \
+  -fsanitize=undefined -fsanitize-address-use-after-scope \
+  -fsanitize-undefined-trap-on-error -fstack-protector
+# Omit -fanalyzer from GCC_DEBUG_FLAGS, as it makes GCC too slow.
+GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
+  $(GCC_INSTRUMENT) \
+  -Wall -Wextra \
+  -Walloc-size-larger-than=100000 -Warray-bounds=2 \
+  -Wbad-function-cast -Wcast-align=strict -Wdate-time \
+  -Wdeclaration-after-statement -Wdouble-promotion \
+  -Wduplicated-branches -Wduplicated-cond \
+  -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \
+  -Winit-self -Wlogical-op \
+  -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \
+  -Wnull-dereference \
+  -Wold-style-definition -Woverlength-strings -Wpointer-arith \
+  -Wshadow -Wshift-overflow=2 -Wstrict-overflow \
+  -Wstrict-prototypes -Wstringop-overflow=4 \
+  -Wstringop-truncation -Wsuggest-attribute=cold \
+  -Wsuggest-attribute=const -Wsuggest-attribute=format \
+  -Wsuggest-attribute=malloc \
+  -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \
+  -Wtrampolines -Wundef -Wuninitialized -Wunused-macros \
+  -Wvariadic-macros -Wvla -Wwrite-strings \
+  -Wno-address -Wno-format-nonliteral -Wno-sign-compare \
+  -Wno-type-limits -Wno-unused-parameter
+#
+# If your system has a "GMT offset" field in its "struct tm"s
+# (or if you decide to add such a field in your system's "time.h" file),
+# add the name to a define such as
+#	-DTM_GMTOFF=tm_gmtoff
+# to the end of the "CFLAGS=" line.  If not defined, the code attempts to
+# guess TM_GMTOFF from other macros; define NO_TM_GMTOFF to suppress this.
+# Similarly, if your system has a "zone abbreviation" field, define
+#	-DTM_ZONE=tm_zone
+# and define NO_TM_ZONE to suppress any guessing.  These two fields are not
+# required by POSIX, but are widely available on GNU/Linux and BSD systems.
+#
+# The next batch of options control support for external variables
+# exported by tzcode.  In practice these variables are less useful
+# than TM_GMTOFF and TM_ZONE.  However, most of them are standardized.
+# #
+# # To omit or support the external variable "tzname", add one of:
+# #	-DHAVE_TZNAME=0 # do not support "tzname"
+# #	-DHAVE_TZNAME=1 # support "tzname", which is defined by system library
+# #	-DHAVE_TZNAME=2 # support and define "tzname"
+# # to the "CFLAGS=" line.  "tzname" is required by POSIX 1988 and later.
+# # If not defined, the code attempts to guess HAVE_TZNAME from other macros.
+# # Warning: unless time_tz is also defined, HAVE_TZNAME=1 can cause
+# # crashes when combined with some platforms' standard libraries,
+# # presumably due to memory allocation issues.
+# #
+# # To omit or support the external variables "timezone" and "daylight", add
+# #	-DUSG_COMPAT=0 # do not support
+# #	-DUSG_COMPAT=1 # support, and variables are defined by system library
+# #	-DUSG_COMPAT=2 # support and define variables
+# # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by
+# # Unix Systems Group code and are required by POSIX 2008 (with XSI) and later.
+# # If not defined, the code attempts to guess USG_COMPAT from other macros.
+# #
+# # To support the external variable "altzone", add
+# #	-DALTZONE=0 # do not support
+# #	-DALTZONE=1 # support "altzone", which is defined by system library
+# #	-DALTZONE=2 # support and define "altzone"
+# # to the end of the "CFLAGS=" line; although "altzone" appeared in
+# # System V Release 3.1 it has not been standardized.
+# # If not defined, the code attempts to guess ALTZONE from other macros.
+#
+# If you want functions that were inspired by early versions of X3J11's work,
+# add
+#	-DSTD_INSPIRED
+# to the end of the "CFLAGS=" line.  This arranges for the functions
+# "offtime", "timelocal", "timegm", "timeoff",
+# "posix2time", and "time2posix" to be added to the time conversion library.
+# "offtime" is like "gmtime" except that it accepts a second (long) argument
+# that gives an offset to add to the time_t when converting it.
+# "timelocal" is equivalent to "mktime".
+# "timegm" is like "timelocal" except that it turns a struct tm into
+# a time_t using UT (rather than local time as "timelocal" does).
+# "timeoff" is like "timegm" except that it accepts a second (long) argument
+# that gives an offset to use when converting to a time_t.
+# "posix2time" and "time2posix" are described in an included manual page.
+# X3J11's work does not describe any of these functions.
+# These functions may well disappear in future releases of the time
+# conversion package.
+#
+# If you don't want functions that were inspired by NetBSD, add
+#	-DNETBSD_INSPIRED=0
+# to the end of the "CFLAGS=" line.  Otherwise, the functions
+# "localtime_rz", "mktime_z", "tzalloc", and "tzfree" are added to the
+# time library, and if STD_INSPIRED is also defined the functions
+# "posix2time_z" and "time2posix_z" are added as well.
+# The functions ending in "_z" (or "_rz") are like their unsuffixed
+# (or suffixed-by-"_r") counterparts, except with an extra first
+# argument of opaque type timezone_t that specifies the timezone.
+# "tzalloc" allocates a timezone_t value, and "tzfree" frees it.
+#
+# If you want to allocate state structures in localtime, add
+#	-DALL_STATE
+# to the end of the "CFLAGS=" line.  Storage is obtained by calling malloc.
+#
+# NIST-PCTS:151-2, Version 1.4, (1993-12-03) is a test suite put
+# out by the National Institute of Standards and Technology
+# which claims to test C and Posix conformance.  If you want to pass PCTS, add
+#	-DPCTS
+# to the end of the "CFLAGS=" line.
+#
+# If you want strict compliance with XPG4 as of 1994-04-09, add
+#	-DXPG4_1994_04_09
+# to the end of the "CFLAGS=" line.  This causes "strftime" to always return
+# 53 as a week number (rather than 52 or 53) for January days before
+# January's first Monday when a "%V" format is used and January 1
+# falls on a Friday, Saturday, or Sunday.
+
+CFLAGS=
+
+# Linker flags.  Default to $(LFLAGS) for backwards compatibility
+# to release 2012h and earlier.
+
+LDFLAGS=	$(LFLAGS)
+
+# For leap seconds, this Makefile uses LEAPSECONDS='-L leapseconds' in
+# submake command lines.  The default is no leap seconds.
+
+LEAPSECONDS=
+
+# The zic command and its arguments.
+
+zic=		./zic
+ZIC=		$(zic) $(ZFLAGS)
+
+# To shrink the size of installed TZif files,
+# append "-r @N" to omit data before N-seconds-after-the-Epoch.
+# To grow the files and work around older application bugs, append "-b fat";
+# see ZIC_BLOAT_DEFAULT above.
+# See the zic man page for more about -b and -r.
+ZFLAGS=
+
+# How to use zic to install TZif files.
+
+ZIC_INSTALL=	$(ZIC) -d '$(DESTDIR)$(TZDIR)' $(LEAPSECONDS)
+
+# The name of a Posix-compliant 'awk' on your system.
+# mawk 1.3.3 and Solaris 10 /usr/bin/awk do not work.
+# Also, it is better (though not essential) if 'awk' supports UTF-8,
+# and unfortunately mawk and busybox awk do not support UTF-8.
+# Try AWK=gawk or AWK=nawk if your awk has the abovementioned problems.
+AWK=		awk
+
+# The full path name of a Posix-compliant shell, preferably one that supports
+# the Korn shell's 'select' statement as an extension.
+# These days, Bash is the most popular.
+# It should be OK to set this to /bin/sh, on platforms where /bin/sh
+# lacks 'select' or doesn't completely conform to Posix, but /bin/bash
+# is typically nicer if it works.
+KSHELL=		/bin/bash
+
+# Name of curl <https://curl.haxx.se/>, used for HTML validation.
+CURL=		curl
+
+# Name of GNU Privacy Guard <https://gnupg.org/>, used to sign distributions.
+GPG=		gpg
+
+# This expensive test requires USE_LTZ.
+# To suppress it, define this macro to be empty.
+CHECK_TIME_T_ALTERNATIVES = check_time_t_alternatives
+
+# SAFE_CHAR is a regular expression that matches a safe character.
+# Some parts of this distribution are limited to safe characters;
+# others can use any UTF-8 character.
+# For now, the safe characters are a safe subset of ASCII.
+# The caller must set the shell variable 'sharp' to the character '#',
+# since Makefile macros cannot contain '#'.
+# TAB_CHAR is a single tab character, in single quotes.
+TAB_CHAR=	'	'
+SAFE_CHARSET1=	$(TAB_CHAR)' !\"'$$sharp'$$%&'\''()*+,./0123456789:;<=>?@'
+SAFE_CHARSET2=	'ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\^_`'
+SAFE_CHARSET3=	'abcdefghijklmnopqrstuvwxyz{|}~'
+SAFE_CHARSET=	$(SAFE_CHARSET1)$(SAFE_CHARSET2)$(SAFE_CHARSET3)
+SAFE_CHAR=	'[]'$(SAFE_CHARSET)'-]'
+
+# These characters are Latin-1, and so are likely to be displayable
+# even in editors with limited character sets.
+UNUSUAL_OK_LATIN_1 = «°±»½¾×
+# This IPA symbol is represented in Unicode as the composition of
+# U+0075 and U+032F, and U+032F is not considered alphabetic by some
+# grep implementations that do not grok composition.
+UNUSUAL_OK_IPA = u̯
+# Non-ASCII non-letters that OK_CHAR allows, as these characters are
+# useful in commentary.
+UNUSUAL_OK_CHARSET= $(UNUSUAL_OK_LATIN_1)$(UNUSUAL_OK_IPA)
+
+# OK_CHAR matches any character allowed in the distributed files.
+# This is the same as SAFE_CHAR, except that UNUSUAL_OK_CHARSET and
+# multibyte letters are also allowed so that commentary can contain a
+# few safe symbols and people's names and can quote non-English sources.
+# Other non-letters are limited to ASCII renderings for the
+# convenience of maintainers using XEmacs 21.5.34, which by default
+# mishandles Unicode characters U+0100 and greater.
+OK_CHAR=	'[][:alpha:]$(UNUSUAL_OK_CHARSET)'$(SAFE_CHARSET)'-]'
+
+# SAFE_LINE matches a line of safe characters.
+# SAFE_SHARP_LINE is similar, except any OK character can follow '#';
+# this is so that comments can contain non-ASCII characters.
+# OK_LINE matches a line of OK characters.
+SAFE_LINE=	'^'$(SAFE_CHAR)'*$$'
+SAFE_SHARP_LINE='^'$(SAFE_CHAR)'*('$$sharp$(OK_CHAR)'*)?$$'
+OK_LINE=	'^'$(OK_CHAR)'*$$'
+
+# Flags to give 'tar' when making a distribution.
+# Try to use flags appropriate for GNU tar.
+GNUTARFLAGS= --format=pax --pax-option='delete=atime,delete=ctime' \
+  --numeric-owner --owner=0 --group=0 \
+  --mode=go+u,go-w --sort=name
+TARFLAGS=	`if tar $(GNUTARFLAGS) --version >/dev/null 2>&1; \
+		 then echo $(GNUTARFLAGS); \
+		 else :; \
+		 fi`
+
+# Flags to give 'gzip' when making a distribution.
+GZIPFLAGS=	-9n
+
+###############################################################################
+
+#MAKE=		make
+
+cc=		cc
+CC=		$(cc) -DTZDIR='"$(TZDIR)"'
+
+AR=		ar
+
+# ':' on typical hosts; 'ranlib' on the ancient hosts that still need ranlib.
+RANLIB=		:
+
+TZCOBJS=	zic.o
+TZDOBJS=	zdump.o localtime.o asctime.o strftime.o
+DATEOBJS=	date.o localtime.o strftime.o asctime.o
+LIBSRCS=	localtime.c asctime.c difftime.c strftime.c
+LIBOBJS=	localtime.o asctime.o difftime.o strftime.o
+HEADERS=	tzfile.h private.h
+NONLIBSRCS=	zic.c zdump.c
+NEWUCBSRCS=	date.c
+SOURCES=	$(HEADERS) $(LIBSRCS) $(NONLIBSRCS) $(NEWUCBSRCS) \
+			tzselect.ksh workman.sh
+MANS=		newctime.3 newstrftime.3 newtzset.3 time2posix.3 \
+			tzfile.5 tzselect.8 zic.8 zdump.8
+MANTXTS=	newctime.3.txt newstrftime.3.txt newtzset.3.txt \
+			time2posix.3.txt \
+			tzfile.5.txt tzselect.8.txt zic.8.txt zdump.8.txt \
+			date.1.txt
+COMMON=		calendars CONTRIBUTING LICENSE Makefile \
+			NEWS README SECURITY theory.html version
+WEB_PAGES=	tz-art.html tz-how-to.html tz-link.html
+CHECK_WEB_PAGES=check_theory.html check_tz-art.html \
+			check_tz-how-to.html check_tz-link.html
+DOCS=		$(MANS) date.1 $(MANTXTS) $(WEB_PAGES)
+PRIMARY_YDATA=	africa antarctica asia australasia \
+		europe northamerica southamerica
+YDATA=		$(PRIMARY_YDATA) etcetera
+NDATA=		factory
+TDATA_TO_CHECK=	$(YDATA) $(NDATA) backward
+TDATA=		$(YDATA) $(NDATA) $(BACKWARD)
+ZONETABLES=	zone1970.tab zone.tab
+TABDATA=	iso3166.tab $(TZDATA_TEXT) $(ZONETABLES)
+LEAP_DEPS=	leapseconds.awk leap-seconds.list
+TZDATA_ZI_DEPS=	ziguard.awk zishrink.awk version $(TDATA) $(PACKRATDATA)
+DSTDATA_ZI_DEPS= ziguard.awk $(TDATA) $(PACKRATDATA)
+DATA=		$(TDATA_TO_CHECK) backzone iso3166.tab leap-seconds.list \
+			leapseconds $(ZONETABLES)
+AWK_SCRIPTS=	checklinks.awk checktab.awk leapseconds.awk \
+			ziguard.awk zishrink.awk
+MISC=		$(AWK_SCRIPTS) zoneinfo2tdf.pl
+TZS_YEAR=	2050
+TZS_CUTOFF_FLAG=	-c $(TZS_YEAR)
+TZS=		to$(TZS_YEAR).tzs
+TZS_NEW=	to$(TZS_YEAR)new.tzs
+TZS_DEPS=	$(YDATA) asctime.c localtime.c \
+			private.h tzfile.h zdump.c zic.c
+# EIGHT_YARDS is just a yard short of the whole ENCHILADA.
+EIGHT_YARDS = $(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) tzdata.zi
+ENCHILADA = $(EIGHT_YARDS) $(TZS)
+
+# Consult these files when deciding whether to rebuild the 'version' file.
+# This list is not the same as the output of 'git ls-files', since
+# .gitignore is not distributed.
+VERSION_DEPS= \
+		calendars CONTRIBUTING LICENSE Makefile NEWS README SECURITY \
+		africa antarctica asctime.c asia australasia \
+		backward backzone \
+		checklinks.awk checktab.awk \
+		date.1 date.c difftime.c \
+		etcetera europe factory iso3166.tab \
+		leap-seconds.list leapseconds.awk localtime.c \
+		newctime.3 newstrftime.3 newtzset.3 northamerica \
+		private.h southamerica strftime.c theory.html \
+		time2posix.3 tz-art.html tz-how-to.html tz-link.html \
+		tzfile.5 tzfile.h tzselect.8 tzselect.ksh \
+		workman.sh zdump.8 zdump.c zic.8 zic.c \
+		ziguard.awk zishrink.awk \
+		zone.tab zone1970.tab zoneinfo2tdf.pl
+
+# And for the benefit of csh users on systems that assume the user
+# shell should be used to handle commands in Makefiles. . .
+
+SHELL=		/bin/sh
+
+all:		tzselect zic zdump libtz.a $(TABDATA) \
+		  vanguard.zi main.zi rearguard.zi
+
+ALL:		all date $(ENCHILADA)
+
+install:	all $(DATA) $(REDO) $(MANS)
+		mkdir -p '$(DESTDIR)$(BINDIR)' \
+			'$(DESTDIR)$(ZDUMPDIR)' '$(DESTDIR)$(ZICDIR)' \
+			'$(DESTDIR)$(LIBDIR)' \
+			'$(DESTDIR)$(MANDIR)/man3' '$(DESTDIR)$(MANDIR)/man5' \
+			'$(DESTDIR)$(MANDIR)/man8'
+		$(ZIC_INSTALL) -l $(LOCALTIME) \
+			`case '$(POSIXRULES)' in ?*) echo '-p';; esac \
+			` $(POSIXRULES) \
+			-t '$(DESTDIR)$(TZDEFAULT)'
+		cp -f $(TABDATA) '$(DESTDIR)$(TZDIR)/.'
+		cp tzselect '$(DESTDIR)$(BINDIR)/.'
+		cp zdump '$(DESTDIR)$(ZDUMPDIR)/.'
+		cp zic '$(DESTDIR)$(ZICDIR)/.'
+		cp libtz.a '$(DESTDIR)$(LIBDIR)/.'
+		$(RANLIB) '$(DESTDIR)$(LIBDIR)/libtz.a'
+		cp -f newctime.3 newtzset.3 '$(DESTDIR)$(MANDIR)/man3/.'
+		cp -f tzfile.5 '$(DESTDIR)$(MANDIR)/man5/.'
+		cp -f tzselect.8 zdump.8 zic.8 '$(DESTDIR)$(MANDIR)/man8/.'
+
+INSTALL:	ALL install date.1
+		mkdir -p '$(DESTDIR)$(BINDIR)' '$(DESTDIR)$(MANDIR)/man1'
+		cp date '$(DESTDIR)$(BINDIR)/.'
+		cp -f date.1 '$(DESTDIR)$(MANDIR)/man1/.'
+
+# Calculate version number from git, if available.
+# Otherwise, use $(VERSION) unless it is "unknown" and there is already
+# a 'version' file, in which case reuse the existing 'version' contents
+# and append "-dirty" if the contents do not already end in "-dirty".
+version:	$(VERSION_DEPS)
+		{ (type git) >/dev/null 2>&1 && \
+		  V=`git describe --match '[0-9][0-9][0-9][0-9][a-z]*' \
+				--abbrev=7 --dirty` || \
+		  if test '$(VERSION)' = unknown && V=`cat $@`; then \
+		    case $$V in *-dirty);; *) V=$$V-dirty;; esac; \
+		  else \
+		    V='$(VERSION)'; \
+		  fi; } && \
+		printf '%s\n' "$$V" >$@.out
+		mv $@.out $@
+
+# These files can be tailored by setting BACKWARD and PACKRATDATA.
+vanguard.zi main.zi rearguard.zi: $(DSTDATA_ZI_DEPS)
+		$(AWK) -v DATAFORM=`expr $@ : '\(.*\).zi'` -f ziguard.awk \
+		  $(TDATA) $(PACKRATDATA) >$@.out
+		mv $@.out $@
+# This file has a version comment that attempts to capture any tailoring
+# via BACKWARD, DATAFORM, PACKRATDATA, and REDO.
+tzdata.zi:	$(DATAFORM).zi version zishrink.awk
+		version=`sed 1q version` && \
+		  LC_ALL=C $(AWK) \
+		    -v dataform='$(DATAFORM)' \
+		    -v deps='$(DSTDATA_ZI_DEPS) zishrink.awk' \
+		    -v redo='$(REDO)' \
+		    -v version="$$version" \
+		    -f zishrink.awk \
+		    $(DATAFORM).zi >$@.out
+		mv $@.out $@
+
+version.h:	version
+		VERSION=`cat version` && printf '%s\n' \
+		  'static char const PKGVERSION[]="($(PACKAGE)) ";' \
+		  "static char const TZVERSION[]=\"$$VERSION\";" \
+		  'static char const REPORT_BUGS_TO[]="$(BUGEMAIL)";' \
+		  >$@.out
+		mv $@.out $@
+
+zdump:		$(TZDOBJS)
+		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS)
+
+zic:		$(TZCOBJS)
+		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS)
+
+leapseconds:	$(LEAP_DEPS)
+		$(AWK) -v EXPIRES_LINE=$(EXPIRES_LINE) \
+		  -f leapseconds.awk leap-seconds.list >$@.out
+		mv $@.out $@
+
+# Arguments to pass to submakes of install_data.
+# They can be overridden by later submake arguments.
+INSTALLARGS = \
+ BACKWARD='$(BACKWARD)' \
+ DESTDIR='$(DESTDIR)' \
+ LEAPSECONDS='$(LEAPSECONDS)' \
+ PACKRATDATA='$(PACKRATDATA)' \
+ TZDEFAULT='$(TZDEFAULT)' \
+ TZDIR='$(TZDIR)' \
+ ZIC='$(ZIC)'
+
+INSTALL_DATA_DEPS = zic leapseconds tzdata.zi
+
+# 'make install_data' installs one set of TZif files.
+install_data: $(INSTALL_DATA_DEPS)
+		$(ZIC_INSTALL) tzdata.zi
+
+posix_only: $(INSTALL_DATA_DEPS)
+		$(MAKE) $(INSTALLARGS) LEAPSECONDS= install_data
+
+right_only: $(INSTALL_DATA_DEPS)
+		$(MAKE) $(INSTALLARGS) LEAPSECONDS='-L leapseconds' \
+			install_data
+
+# In earlier versions of this makefile, the other two directories were
+# subdirectories of $(TZDIR).  However, this led to configuration errors.
+# For example, with posix_right under the earlier scheme,
+# TZ='right/Australia/Adelaide' got you localtime with leap seconds,
+# but gmtime without leap seconds, which led to problems with applications
+# like sendmail that subtract gmtime from localtime.
+# Therefore, the other two directories are now siblings of $(TZDIR).
+# You must replace all of $(TZDIR) to switch from not using leap seconds
+# to using them, or vice versa.
+right_posix:	right_only
+		rm -fr '$(DESTDIR)$(TZDIR)-leaps'
+		ln -s '$(TZDIR_BASENAME)' '$(DESTDIR)$(TZDIR)-leaps' || \
+		  $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-leaps' right_only
+		$(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-posix' posix_only
+
+posix_right:	posix_only
+		rm -fr '$(DESTDIR)$(TZDIR)-posix'
+		ln -s '$(TZDIR_BASENAME)' '$(DESTDIR)$(TZDIR)-posix' || \
+		  $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-posix' posix_only
+		$(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-leaps' right_only
+
+# This obsolescent rule is present for backwards compatibility with
+# tz releases 2014g through 2015g.  It should go away eventually.
+posix_packrat: $(INSTALL_DATA_DEPS)
+		$(MAKE) $(INSTALLARGS) PACKRATDATA=backzone posix_only
+
+zones:		$(REDO)
+
+# dummy.zd is not a real file; it is mentioned here only so that the
+# top-level 'make' does not have a syntax error.
+ZDS = dummy.zd
+# Rule used only by submakes invoked by the $(TZS_NEW) rule.
+# It is separate so that GNU 'make -j' can run instances in parallel.
+$(ZDS): zdump
+		./zdump -i $(TZS_CUTOFF_FLAG) '$(wd)/'$$(expr $@ : '\(.*\).zd') \
+		  >$@
+
+TZS_NEW_DEPS = tzdata.zi zdump zic
+$(TZS_NEW): $(TZS_NEW_DEPS)
+		rm -fr tzs$(TZS_YEAR).dir
+		mkdir tzs$(TZS_YEAR).dir
+		$(zic) -d tzs$(TZS_YEAR).dir tzdata.zi
+		$(AWK) '/^L/{print "Link\t" $$2 "\t" $$3}' \
+		   tzdata.zi | LC_ALL=C sort >$@.out
+		wd=`pwd` && \
+		x=`$(AWK) '/^Z/{print "tzs$(TZS_YEAR).dir/" $$2 ".zd"}' \
+				tzdata.zi \
+			| LC_ALL=C sort -t . -k 2,2` && \
+		set x $$x && \
+		shift && \
+		ZDS=$$* && \
+		$(MAKE) wd="$$wd" TZS_CUTOFF_FLAG="$(TZS_CUTOFF_FLAG)" \
+		  ZDS="$$ZDS" $$ZDS && \
+		sed 's,^TZ=".*\.dir/,TZ=",' $$ZDS >>$@.out
+		rm -fr tzs$(TZS_YEAR).dir
+		mv $@.out $@
+
+# If $(TZS) exists but 'make check_tzs' fails, a maintainer should inspect the
+# failed output and fix the inconsistency, perhaps by running 'make force_tzs'.
+$(TZS):
+		touch $@
+
+force_tzs:	$(TZS_NEW)
+		cp $(TZS_NEW) $(TZS)
+
+libtz.a:	$(LIBOBJS)
+		rm -f $@
+		$(AR) -rc $@ $(LIBOBJS)
+		$(RANLIB) $@
+
+date:		$(DATEOBJS)
+		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(DATEOBJS) $(LDLIBS)
+
+tzselect:	tzselect.ksh version
+		VERSION=`cat version` && sed \
+			-e 's|#!/bin/bash|#!$(KSHELL)|g' \
+			-e 's|AWK=[^}]*|AWK='\''$(AWK)'\''|g' \
+			-e 's|\(PKGVERSION\)=.*|\1='\''($(PACKAGE)) '\''|' \
+			-e 's|\(REPORT_BUGS_TO\)=.*|\1=$(BUGEMAIL)|' \
+			-e 's|TZDIR=[^}]*|TZDIR=$(TZDIR)|' \
+			-e 's|\(TZVERSION\)=.*|\1='"$$VERSION"'|' \
+			<$@.ksh >$@.out
+		chmod +x $@.out
+		mv $@.out $@
+
+check:		check_character_set check_white_space check_links \
+		  check_name_lengths check_sorted \
+		  check_tables check_web check_zishrink check_tzs
+
+check_character_set: $(ENCHILADA)
+	test ! '$(UTF8_LOCALE)' || \
+	! printf 'A\304\200B\n' | \
+	  LC_ALL='$(UTF8_LOCALE)' grep -q '^A.B$$' >/dev/null 2>&1 || { \
+		LC_ALL='$(UTF8_LOCALE)' && export LC_ALL && \
+		sharp='#' && \
+		! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \
+			$(MISC) $(SOURCES) $(WEB_PAGES) \
+			CONTRIBUTING LICENSE README SECURITY \
+			version tzdata.zi && \
+		! grep -Env $(SAFE_LINE)'|^UNUSUAL_OK_'$(OK_CHAR)'*$$' \
+			Makefile && \
+		! grep -Env $(SAFE_SHARP_LINE) $(TDATA_TO_CHECK) backzone \
+			leapseconds zone.tab && \
+		! grep -Env $(OK_LINE) $(ENCHILADA); \
+	}
+	touch $@
+
+check_white_space: $(ENCHILADA)
+		patfmt=' \t|[\f\r\v]' && pat=`printf "$$patfmt\\n"` && \
+		! grep -En "$$pat" \
+			$$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list)
+		! grep -n '[[:space:]]$$' \
+			$$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list)
+		touch $@
+
+PRECEDES_FILE_NAME = ^(Zone|Link[[:space:]]+[^[:space:]]+)[[:space:]]+
+FILE_NAME_COMPONENT_TOO_LONG = \
+  $(PRECEDES_FILE_NAME)[^[:space:]]*[^/[:space:]]{15}
+
+check_name_lengths: $(TDATA_TO_CHECK) backzone
+		! grep -En '$(FILE_NAME_COMPONENT_TOO_LONG)' \
+			$(TDATA_TO_CHECK) backzone
+		touch $@
+
+CHECK_CC_LIST = { n = split($$1,a,/,/); for (i=2; i<=n; i++) print a[1], a[i]; }
+
+check_sorted: backward backzone iso3166.tab zone.tab zone1970.tab
+		$(AWK) '/^Link/ {print $$3}' backward | LC_ALL=C sort -cu
+		$(AWK) '/^Zone/ {print $$2}' backzone | LC_ALL=C sort -cu
+		touch $@
+
+check_links:	checklinks.awk $(TDATA_TO_CHECK) tzdata.zi
+		$(AWK) -f checklinks.awk $(TDATA_TO_CHECK)
+		$(AWK) -f checklinks.awk tzdata.zi
+		touch $@
+
+check_tables:	checktab.awk $(YDATA) backward $(ZONETABLES)
+		for tab in $(ZONETABLES); do \
+		  test "$$tab" = zone.tab && links='$(BACKWARD)' || links=''; \
+		  $(AWK) -f checktab.awk -v zone_table=$$tab $(YDATA) $$links \
+		    || exit; \
+		done
+		touch $@
+
+check_tzs:	$(TZS) $(TZS_NEW)
+		if test -s $(TZS); then \
+		  diff -u $(TZS) $(TZS_NEW); \
+		else \
+		  cp $(TZS_NEW) $(TZS); \
+		fi
+		touch $@
+
+check_web:	$(CHECK_WEB_PAGES)
+check_theory.html: theory.html
+check_tz-art.html: tz-art.html
+check_tz-how-to.html: tz-how-to.html
+check_tz-link.html: tz-link.html
+check_theory.html check_tz-art.html check_tz-how-to.html check_tz-link.html:
+		$(CURL) -sS --url https://validator.w3.org/nu/ -F out=gnu \
+		    -F file=@$$(expr $@ : 'check_\(.*\)') -o $@.out && \
+		  test ! -s $@.out || { cat $@.out; exit 1; }
+		mv $@.out $@
+
+# Check that zishrink.awk does not alter the data, and that ziguard.awk
+# preserves main-format data.
+check_zishrink: check_zishrink_posix check_zishrink_right
+check_zishrink_posix check_zishrink_right: \
+  zic leapseconds $(PACKRATDATA) $(TDATA) $(DATAFORM).zi tzdata.zi
+		rm -fr $@.dir $@-t.dir $@-shrunk.dir
+		mkdir $@.dir $@-t.dir $@-shrunk.dir
+		case $@ in \
+		  *_right) leap='-L leapseconds';; \
+		  *) leap=;; \
+		esac && \
+		  $(ZIC) $$leap -d $@.dir $(DATAFORM).zi && \
+		  $(ZIC) $$leap -d $@-shrunk.dir tzdata.zi && \
+		  case $(DATAFORM) in \
+		    main) \
+		      $(ZIC) $$leap -d $@-t.dir $(TDATA) && \
+		      $(AWK) '/^Rule/' $(TDATA) | \
+			$(ZIC) $$leap -d $@-t.dir - $(PACKRATDATA) && \
+		      diff -r $@.dir $@-t.dir;; \
+		  esac
+		diff -r $@.dir $@-shrunk.dir
+		rm -fr $@.dir $@-t.dir $@-shrunk.dir
+		touch $@
+
+clean_misc:
+		rm -fr check_*.dir
+		rm -f *.o *.out $(TIME_T_ALTERNATIVES) \
+		  check_* core typecheck_* \
+		  date tzselect version.h zdump zic libtz.a
+clean:		clean_misc
+		rm -fr *.dir tzdb-*/
+		rm -f *.zi $(TZS_NEW)
+
+maintainer-clean: clean
+		@echo 'This command is intended for maintainers to use; it'
+		@echo 'deletes files that may need special tools to rebuild.'
+		rm -f leapseconds version $(MANTXTS) $(TZS) *.asc *.tar.*
+
+names:
+		@echo $(ENCHILADA)
+
+public:		check check_public $(CHECK_TIME_T_ALTERNATIVES) \
+		tarballs signatures
+
+date.1.txt:	date.1
+newctime.3.txt:	newctime.3
+newstrftime.3.txt: newstrftime.3
+newtzset.3.txt:	newtzset.3
+time2posix.3.txt: time2posix.3
+tzfile.5.txt:	tzfile.5
+tzselect.8.txt:	tzselect.8
+zdump.8.txt:	zdump.8
+zic.8.txt:	zic.8
+
+$(MANTXTS):	workman.sh
+		LC_ALL=C sh workman.sh `expr $@ : '\(.*\)\.txt$$'` >$@.out
+		mv $@.out $@
+
+# Set file timestamps deterministically if possible,
+# so that tarballs containing the timestamps are reproducible.
+#
+# '$(SET_TIMESTAMP_N) N DEST A B C ...' sets the timestamp of the
+# file DEST to the maximum of the timestamps of the files A B C ...,
+# plus N if GNU ls and touch are available.
+SET_TIMESTAMP_N = sh -c '\
+  n=$$0 dest=$$1; shift; \
+  touch -cmr `ls -t "$$@" | sed 1q` "$$dest" && \
+  if test $$n != 0 && \
+     lsout=`ls -n --time-style="+%s" "$$dest" 2>/dev/null`; then \
+    set x $$lsout && \
+    touch -cmd @`expr $$7 + $$n` "$$dest"; \
+  else :; fi'
+# If DEST depends on A B C ... in this Makefile, callers should use
+# $(SET_TIMESTAMP_DEP) DEST A B C ..., for the benefit of any
+# downstream 'make' that considers equal timestamps to be out of date.
+# POSIX allows this 'make' behavior, and HP-UX 'make' does it.
+# If all that matters is that the timestamp be reproducible
+# and plausible, use $(SET_TIMESTAMP).
+SET_TIMESTAMP = $(SET_TIMESTAMP_N) 0
+SET_TIMESTAMP_DEP = $(SET_TIMESTAMP_N) 1
+
+# Set the timestamps to those of the git repository, if available,
+# and if the files have not changed since then.
+# This uses GNU 'ls --time-style=+%s', which outputs the seconds count,
+# and GNU 'touch -d@N FILE', where N is the number of seconds since 1970.
+# If git or GNU is absent, don't bother to sync with git timestamps.
+# Also, set the timestamp of each prebuilt file like 'leapseconds'
+# to be the maximum of the files it depends on.
+set-timestamps.out: $(EIGHT_YARDS)
+		rm -f $@
+		if (type git) >/dev/null 2>&1 && \
+		   files=`git ls-files $(EIGHT_YARDS)` && \
+		   touch -md @1 test.out; then \
+		  rm -f test.out && \
+		  for file in $$files; do \
+		    if git diff --quiet $$file; then \
+		      time=`git log -1 --format='tformat:%ct' $$file` && \
+		      touch -cmd @$$time $$file; \
+		    else \
+		      echo >&2 "$$file: warning: does not match repository"; \
+		    fi || exit; \
+		  done; \
+		fi
+		$(SET_TIMESTAMP_DEP) leapseconds $(LEAP_DEPS)
+		for file in `ls $(MANTXTS) | sed 's/\.txt$$//'`; do \
+		  $(SET_TIMESTAMP_DEP) $$file.txt $$file workman.sh || \
+		    exit; \
+		done
+		$(SET_TIMESTAMP_DEP) version $(VERSION_DEPS)
+		$(SET_TIMESTAMP_DEP) tzdata.zi $(TZDATA_ZI_DEPS)
+		touch $@
+set-tzs-timestamp.out: $(TZS)
+		$(SET_TIMESTAMP_DEP) $(TZS) $(TZS_DEPS)
+		touch $@
+
+# The zics below ensure that each data file can stand on its own.
+# We also do an all-files run to catch links to links.
+
+check_public: $(VERSION_DEPS)
+		rm -fr public.dir
+		mkdir public.dir
+		ln $(VERSION_DEPS) public.dir
+		cd public.dir && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' ALL
+		for i in $(TDATA_TO_CHECK) public.dir/tzdata.zi \
+		    public.dir/vanguard.zi public.dir/main.zi \
+		    public.dir/rearguard.zi; \
+		do \
+		  public.dir/zic -v -d public.dir/zoneinfo $$i 2>&1 || exit; \
+		done
+		public.dir/zic -v -d public.dir/zoneinfo-all $(TDATA_TO_CHECK)
+		:
+		: Also check 'backzone' syntax.
+		rm public.dir/main.zi
+		cd public.dir && $(MAKE) PACKRATDATA=backzone main.zi
+		public.dir/zic -d public.dir/zoneinfo main.zi
+		:
+		rm -fr public.dir
+		touch $@
+
+# Check that the code works under various alternative
+# implementations of time_t.
+check_time_t_alternatives: $(TIME_T_ALTERNATIVES)
+$(TIME_T_ALTERNATIVES_TAIL): $(TIME_T_ALTERNATIVES_HEAD)
+$(TIME_T_ALTERNATIVES): $(VERSION_DEPS)
+		rm -fr $@.dir
+		mkdir $@.dir
+		ln $(VERSION_DEPS) $@.dir
+		case $@ in \
+		  int*32_t) range=-2147483648,2147483648;; \
+		  u*) range=0,4294967296;; \
+		  *) range=-4294967296,4294967296;; \
+		esac && \
+		wd=`pwd` && \
+		zones=`$(AWK) '/^[^#]/ { print $$3 }' <zone1970.tab` && \
+		if test $@ = $(TIME_T_ALTERNATIVES_HEAD); then \
+		  range_target=; \
+		else \
+		  range_target=to$$range.tzs; \
+		fi && \
+		(cd $@.dir && \
+		  $(MAKE) TOPDIR="$$wd/$@.dir" \
+		    CFLAGS='$(CFLAGS) -Dtime_tz='"'$@'" \
+		    REDO='$(REDO)' \
+			D=$$wd/$@.dir \
+		    TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \
+		    install $$range_target) && \
+		test $@ = $(TIME_T_ALTERNATIVES_HEAD) || { \
+		  (cd $(TIME_T_ALTERNATIVES_HEAD).dir && \
+		    $(MAKE) TOPDIR="$$wd/$@.dir" \
+		      TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \
+			D=$$wd/$@.dir \
+		      to$$range.tzs) && \
+		  diff -u $(TIME_T_ALTERNATIVES_HEAD).dir/to$$range.tzs \
+			  $@.dir/to$$range.tzs && \
+		  if diff -q Makefile Makefile 2>/dev/null; then \
+		    quiet_option='-q'; \
+		  else \
+		    quiet_option=''; \
+		  fi && \
+		    diff $$quiet_option -r $(TIME_T_ALTERNATIVES_HEAD).dir/etc \
+					   $@.dir/etc && \
+		    diff $$quiet_option -r \
+		      $(TIME_T_ALTERNATIVES_HEAD).dir/usr/share \
+		      $@.dir/usr/share; \
+		}
+		touch $@
+
+TRADITIONAL_ASC = \
+  tzcode$(VERSION).tar.gz.asc \
+  tzdata$(VERSION).tar.gz.asc
+REARGUARD_ASC = \
+  tzdata$(VERSION)-rearguard.tar.gz.asc
+ALL_ASC = $(TRADITIONAL_ASC) $(REARGUARD_ASC) \
+  tzdb-$(VERSION).tar.lz.asc
+
+tarballs rearguard_tarballs traditional_tarballs \
+signatures rearguard_signatures traditional_signatures: \
+  version set-timestamps.out rearguard.zi
+		VERSION=`cat version` && \
+		$(MAKE) AWK='$(AWK)' VERSION="$$VERSION" $@_version
+
+# These *_version rules are intended for use if VERSION is set by some
+# other means.  Ordinarily these rules are used only by the above
+# non-_version rules, which set VERSION on the 'make' command line.
+tarballs_version: traditional_tarballs_version rearguard_tarballs_version \
+  tzdb-$(VERSION).tar.lz
+rearguard_tarballs_version: \
+  tzdata$(VERSION)-rearguard.tar.gz
+traditional_tarballs_version: \
+  tzcode$(VERSION).tar.gz tzdata$(VERSION).tar.gz
+signatures_version: $(ALL_ASC)
+rearguard_signatures_version: $(REARGUARD_ASC)
+traditional_signatures_version: $(TRADITIONAL_ASC)
+
+tzcode$(VERSION).tar.gz: set-timestamps.out
+		LC_ALL=C && export LC_ALL && \
+		tar $(TARFLAGS) -cf - \
+		    $(COMMON) $(DOCS) $(SOURCES) | \
+		  gzip $(GZIPFLAGS) >$@.out
+		mv $@.out $@
+
+tzdata$(VERSION).tar.gz: set-timestamps.out
+		LC_ALL=C && export LC_ALL && \
+		tar $(TARFLAGS) -cf - $(COMMON) $(DATA) $(MISC) | \
+		  gzip $(GZIPFLAGS) >$@.out
+		mv $@.out $@
+
+tzdata$(VERSION)-rearguard.tar.gz: rearguard.zi set-timestamps.out
+		rm -fr tzdata$(VERSION)-rearguard.dir
+		mkdir tzdata$(VERSION)-rearguard.dir
+		ln $(COMMON) $(DATA) $(MISC) tzdata$(VERSION)-rearguard.dir
+		cd tzdata$(VERSION)-rearguard.dir && \
+		  rm -f $(TDATA) $(PACKRATDATA) version
+		for f in $(TDATA) $(PACKRATDATA); do \
+		  rearf=tzdata$(VERSION)-rearguard.dir/$$f; \
+		  $(AWK) -v DATAFORM=rearguard -f ziguard.awk $$f >$$rearf && \
+		  $(SET_TIMESTAMP_DEP) $$rearf ziguard.awk $$f || exit; \
+		done
+		sed '1s/$$/-rearguard/' \
+		  <version >tzdata$(VERSION)-rearguard.dir/version
+		: The dummy pacificnew pacifies TZUpdater 2.3.1 and earlier.
+		TZ=UTC0 touch -mt 202010122253.00 \
+		  tzdata$(VERSION)-rearguard.dir/pacificnew
+		touch -cmr version tzdata$(VERSION)-rearguard.dir/version
+		LC_ALL=C && export LC_ALL && \
+		  (cd tzdata$(VERSION)-rearguard.dir && \
+		   tar $(TARFLAGS) -cf - \
+			$(COMMON) $(DATA) $(MISC) pacificnew | \
+		     gzip $(GZIPFLAGS)) >$@.out
+		mv $@.out $@
+
+tzdb-$(VERSION).tar.lz: set-timestamps.out set-tzs-timestamp.out
+		rm -fr tzdb-$(VERSION)
+		mkdir tzdb-$(VERSION)
+		ln $(ENCHILADA) tzdb-$(VERSION)
+		$(SET_TIMESTAMP) tzdb-$(VERSION) tzdb-$(VERSION)/*
+		LC_ALL=C && export LC_ALL && \
+		tar $(TARFLAGS) -cf - tzdb-$(VERSION) | lzip -9 >$@.out
+		mv $@.out $@
+
+tzcode$(VERSION).tar.gz.asc: tzcode$(VERSION).tar.gz
+tzdata$(VERSION).tar.gz.asc: tzdata$(VERSION).tar.gz
+tzdata$(VERSION)-rearguard.tar.gz.asc: tzdata$(VERSION)-rearguard.tar.gz
+tzdb-$(VERSION).tar.lz.asc: tzdb-$(VERSION).tar.lz
+$(ALL_ASC):
+		$(GPG) --armor --detach-sign $?
+
+TYPECHECK_CFLAGS = $(CFLAGS) -DTYPECHECK -D__time_t_defined -D_TIME_T
+typecheck: typecheck_long_long typecheck_unsigned
+typecheck_long_long typecheck_unsigned: $(VERSION_DEPS)
+		rm -fr $@.dir
+		mkdir $@.dir
+		ln $(VERSION_DEPS) $@.dir
+		cd $@.dir && \
+		  case $@ in \
+		    *_long_long) i="long long";; \
+		    *_unsigned ) i="unsigned" ;; \
+		  esac && \
+		  typecheck_cflags='' && \
+		  $(MAKE) \
+		    CFLAGS="$(TYPECHECK_CFLAGS) \"-Dtime_t=$$i\"" \
+		    TOPDIR="`pwd`" \
+		    install
+		$@.dir/zdump -i -c 1970,1971 Europe/Rome
+		touch $@
+
+zonenames:	tzdata.zi
+		@$(AWK) '/^Z/ { print $$2 } /^L/ { print $$3 }' tzdata.zi
+
+asctime.o:	private.h tzfile.h
+date.o:		private.h
+difftime.o:	private.h
+localtime.o:	private.h tzfile.h
+strftime.o:	private.h tzfile.h
+zdump.o:	version.h
+zic.o:		private.h tzfile.h version.h
+
+.PHONY: ALL INSTALL all
+.PHONY: check check_time_t_alternatives
+.PHONY: check_web check_zishrink
+.PHONY: clean clean_misc dummy.zd force_tzs
+.PHONY: install install_data maintainer-clean names
+.PHONY: posix_only posix_packrat posix_right public
+.PHONY: rearguard_signatures rearguard_signatures_version
+.PHONY: rearguard_tarballs rearguard_tarballs_version
+.PHONY: right_only right_posix signatures signatures_version
+.PHONY: tarballs tarballs_version
+.PHONY: traditional_signatures traditional_signatures_version
+.PHONY: traditional_tarballs traditional_tarballs_version
+.PHONY: typecheck
+.PHONY: zonenames zones
+.PHONY: $(ZDS)
diff --git a/NEWS b/tz/NEWS
index ae44be2..ae44be2 100644
--- a/NEWS
+++ b/tz/NEWS
diff --git a/README b/tz/README
index 145aacd..145aacd 100644
--- a/README
+++ b/tz/README
diff --git a/SECURITY b/tz/SECURITY
index 40128bc..40128bc 100644
--- a/SECURITY
+++ b/tz/SECURITY
diff --git a/africa b/tz/africa
index 4bf491e..4bf491e 100644
--- a/africa
+++ b/tz/africa
diff --git a/antarctica b/tz/antarctica
index 70a5422..70a5422 100644
--- a/antarctica
+++ b/tz/antarctica
diff --git a/asctime.c b/tz/asctime.c
index 56c54b3..56c54b3 100644
--- a/asctime.c
+++ b/tz/asctime.c
diff --git a/asia b/tz/asia
index 049b35c..049b35c 100644
--- a/asia
+++ b/tz/asia
diff --git a/australasia b/tz/australasia
index 77c2c69..77c2c69 100644
--- a/australasia
+++ b/tz/australasia
diff --git a/backward b/tz/backward
index 7685c74..7685c74 100644
--- a/backward
+++ b/tz/backward
diff --git a/backzone b/tz/backzone
index 879a140..879a140 100644
--- a/backzone
+++ b/tz/backzone
diff --git a/calendars b/tz/calendars
index 8bc7062..8bc7062 100644
--- a/calendars
+++ b/tz/calendars
diff --git a/checklinks.awk b/tz/checklinks.awk
index f309010..f309010 100644
--- a/checklinks.awk
+++ b/tz/checklinks.awk
diff --git a/checktab.awk b/tz/checktab.awk
index 23e0a3a..23e0a3a 100644
--- a/checktab.awk
+++ b/tz/checktab.awk
diff --git a/date.1 b/tz/date.1
index 1ecd63a..1ecd63a 100644
--- a/date.1
+++ b/tz/date.1
diff --git a/date.c b/tz/date.c
index b04d3f2..b04d3f2 100644
--- a/date.c
+++ b/tz/date.c
diff --git a/difftime.c b/tz/difftime.c
index ff78f03..ff78f03 100644
--- a/difftime.c
+++ b/tz/difftime.c
diff --git a/etcetera b/tz/etcetera
index 1dc7411..1dc7411 100644
--- a/etcetera
+++ b/tz/etcetera
diff --git a/europe b/tz/europe
index 208585d..208585d 100644
--- a/europe
+++ b/tz/europe
diff --git a/factory b/tz/factory
index 9f5fc33..9f5fc33 100644
--- a/factory
+++ b/tz/factory
diff --git a/iso3166.tab b/tz/iso3166.tab
index a4ff61a..a4ff61a 100644
--- a/iso3166.tab
+++ b/tz/iso3166.tab
diff --git a/leap-seconds.list b/tz/leap-seconds.list
index 0f43115..0f43115 100644
--- a/leap-seconds.list
+++ b/tz/leap-seconds.list
diff --git a/leapseconds.awk b/tz/leapseconds.awk
index b6c48bc..b6c48bc 100755
--- a/leapseconds.awk
+++ b/tz/leapseconds.awk
diff --git a/localtime.c b/tz/localtime.c
index 913c7e8..913c7e8 100644
--- a/localtime.c
+++ b/tz/localtime.c
diff --git a/newctime.3 b/tz/newctime.3
index 1b1790f..1b1790f 100644
--- a/newctime.3
+++ b/tz/newctime.3
diff --git a/newstrftime.3 b/tz/newstrftime.3
index d68bc33..d68bc33 100644
--- a/newstrftime.3
+++ b/tz/newstrftime.3
diff --git a/newtzset.3 b/tz/newtzset.3
index 8aaa0ff..8aaa0ff 100644
--- a/newtzset.3
+++ b/tz/newtzset.3
diff --git a/northamerica b/tz/northamerica
index fb5c94b..fb5c94b 100644
--- a/northamerica
+++ b/tz/northamerica
diff --git a/private.h b/tz/private.h
index e8c0942..e8c0942 100644
--- a/private.h
+++ b/tz/private.h
diff --git a/southamerica b/tz/southamerica
index c6249cd..c6249cd 100644
--- a/southamerica
+++ b/tz/southamerica
diff --git a/strftime.c b/tz/strftime.c
index 5273155..5273155 100644
--- a/strftime.c
+++ b/tz/strftime.c
diff --git a/theory.html b/tz/theory.html
index 28cc88e..28cc88e 100644
--- a/theory.html
+++ b/tz/theory.html
diff --git a/time2posix.3 b/tz/time2posix.3
index 2ea7edc..2ea7edc 100644
--- a/time2posix.3
+++ b/tz/time2posix.3
diff --git a/tz-art.html b/tz/tz-art.html
index 73be9f9..73be9f9 100644
--- a/tz-art.html
+++ b/tz/tz-art.html
diff --git a/tz-how-to.html b/tz/tz-how-to.html
index bf3e86f..bf3e86f 100644
--- a/tz-how-to.html
+++ b/tz/tz-how-to.html
diff --git a/tz-link.html b/tz/tz-link.html
index 92da48f..92da48f 100644
--- a/tz-link.html
+++ b/tz/tz-link.html
diff --git a/tzfile.5 b/tz/tzfile.5
index 550b31d..550b31d 100644
--- a/tzfile.5
+++ b/tz/tzfile.5
diff --git a/tzfile.h b/tz/tzfile.h
index 9c3ea4e..9c3ea4e 100644
--- a/tzfile.h
+++ b/tz/tzfile.h
diff --git a/tzselect.8 b/tz/tzselect.8
index 69514e2..69514e2 100644
--- a/tzselect.8
+++ b/tz/tzselect.8
diff --git a/tzselect.ksh b/tz/tzselect.ksh
index 7b6b789..7b6b789 100644
--- a/tzselect.ksh
+++ b/tz/tzselect.ksh
diff --git a/workman.sh b/tz/workman.sh
index 8fb18a4..8fb18a4 100644
--- a/workman.sh
+++ b/tz/workman.sh
diff --git a/zdump.8 b/tz/zdump.8
index 131a6cb..131a6cb 100644
--- a/zdump.8
+++ b/tz/zdump.8
diff --git a/zdump.c b/tz/zdump.c
index 8b6788a..8b6788a 100644
--- a/zdump.c
+++ b/tz/zdump.c
diff --git a/zic.8 b/tz/zic.8
index a0a9743..a0a9743 100644
--- a/zic.8
+++ b/tz/zic.8
diff --git a/zic.c b/tz/zic.c
index 2d1a187..2d1a187 100644
--- a/zic.c
+++ b/tz/zic.c
diff --git a/ziguard.awk b/tz/ziguard.awk
index 2be6d52..2be6d52 100644
--- a/ziguard.awk
+++ b/tz/ziguard.awk
diff --git a/zishrink.awk b/tz/zishrink.awk
index 1947c7c..1947c7c 100644
--- a/zishrink.awk
+++ b/tz/zishrink.awk
diff --git a/zone.tab b/tz/zone.tab
index 086458f..086458f 100644
--- a/zone.tab
+++ b/tz/zone.tab
diff --git a/zone1970.tab b/tz/zone1970.tab
index c614be8..c614be8 100644
--- a/zone1970.tab
+++ b/tz/zone1970.tab
diff --git a/zoneinfo2tdf.pl b/tz/zoneinfo2tdf.pl
index 176fce9..176fce9 100755
--- a/zoneinfo2tdf.pl
+++ b/tz/zoneinfo2tdf.pl