From 8eeefc360913ce56f8759c33b31e00542a0d3078 Mon Sep 17 00:00:00 2001 From: Stuart Bishop Date: Sun, 2 Oct 2022 15:50:54 +1100 Subject: Squashed 'tz/' changes from b61a7acb4..82693eb52 0fc8f915a Release 2022d 43d32e3a6 tzselect.ksh: mention nawk (the one true awk) 2d49828e3 * asia: Add Palestine URL (thanks to Heba Hamad). 1a0e30a84 Tweak expression of Palestine transition b6e732290 Fix NEWS typo in previous change c42d108da Palestine transitions are now Saturdays at 02:00 92e33b2fb backzone: Uzhhorod comment fix (thanks to Garrett Wollman) d25f00b73 * europe: Comment fix (thanks to Philip Paeps). 2ea205765 Fix commentary in previous change 4dffd914c Simplify three Ukraine zones to one 54e8becfa Additional sourcing for Crimea 2014 switch a339d366d * southamerica: Add decree (thanks to Eduardo Romero Urra). aca1a7057 Fix some post-1970 PACKRATLIST glitches ce4d77644 Release 2022c 747f4a0e1 Spelling/capitalization fixes 4307b3a9d Update some documentation and commentary aa7019f99 Prefer " to ' in HTML attributes c9ba895d3 Remove zoneinfo2tdf.pl e5f99199f Improve tzselect behavior for Turkey etc. 0b9b27e60 Fix bug with 'zic -d /a/b/c' if /a is unwriteable d7f86ac32 Port .txt generation to macOS e8171130f Work around macOS awk bug git-subtree-dir: tz git-subtree-split: 82693eb525a29a10ec95e9fddf31cb683b124d32 --- theory.html | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) (limited to 'theory.html') diff --git a/theory.html b/theory.html index 2b14c51..56390ae 100644 --- a/theory.html +++ b/theory.html @@ -122,7 +122,7 @@ If geolocation information is available, a selection interface can locate the user on a timezone map or prioritize names that are geographically close. For an example selection interface, see the tzselect program in the tz code. -The Unicode Common Locale Data +The Unicode Common Locale Data Repository contains data that may be useful for other selection interfaces; it maps timezone names like Europe/Prague to locale-dependent strings like "Prague", "Praha", "Прага", and "布拉格". @@ -571,7 +571,7 @@ in decreasing order of importance: locations while uninhabited. The leading '-' is a flag that the UT offset is in some sense undefined; this notation is derived - from Internet + from Internet RFC 3339. @@ -624,7 +624,7 @@ Errors in the tz database arise from many sources: should be observed. In her 2015 book The + href="https://www.hup.harvard.edu/catalog.php?isbn=9780674286146">The Global Transformation of Time, 1870–1950, Vanessa Ogle writes "Outside of Europe and North America there was no system of time @@ -810,7 +810,7 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes See: Stephenson FR, Morrison LV, Hohenkerk CY. Measurement of the Earth's rotation: 720 BC to AD 2015. - Proc Royal Soc A. 2016 Dec 7;472:20160404. + Proc Royal Soc A. 2016;472:20160404. Also see: Espenak F. Uncertainty in Delta T (ΔT). @@ -1036,7 +1036,7 @@ an older zic. and numeric data as described above. The file's format is TZif, a timezone information format that contains binary data; see - Internet + Internet RFC 8536. The daylight saving time rules to be used for a particular timezone are encoded in the @@ -1064,11 +1064,12 @@ an older zic.
  • The code supports platforms with a UT offset member - in struct tm, e.g., tm_gmtoff. -
    • -
  • - The code supports platforms with a time zone abbreviation member in - struct tm, e.g., tm_zone. + in struct tm, e.g., tm_gmtoff, + or with a time zone abbreviation member in + struct tm, e.g., tm_zone. As noted + in Austin + Group defect 1533, a future version of POSIX is planned to + require tm_gmtoff and tm_zone.
  • Functions tzalloc, tzfree, @@ -1129,7 +1130,8 @@ The vestigial APIs are: APIs. Although it can still be used in arguments to mktime to disambiguate timestamps near - a DST transition when the clock jumps back, this + a DST transition when the clock jumps back on + platforms lacking tm_gmtoff, this disambiguation does not work when standard time itself jumps back, which can occur when a location changes to a time zone with a lesser UT offset. @@ -1277,7 +1279,7 @@ the operating system kernel clock as described in Precision timekeeping, and this package by default installs a leapseconds file commonly used by -NTP +NTP software that adjusts the kernel clock. However, kernel-clock twiddling approximates UTC only roughly, and systems needing more-precise UTC can use this package's leap -- cgit v1.2.1