* tzfile.h: Add/update implementation limit commentary.

1 files changed, 5 insertions, 1 deletions

diff --git a/tzfile.h b/tzfile.h
index 6b18d6b..9cbdcff 100644
--- a/tzfile.h
+++ b/tzfile.h
@@ -103,20 +103,24 @@ struct tzhead {
 */
 
 #ifndef TZ_MAX_TIMES
+/* This must be at least 242 for Europe/London with 'zic -b fat'.  */
 # define TZ_MAX_TIMES 2000
 #endif /* !defined TZ_MAX_TIMES */
 
 #ifndef TZ_MAX_TYPES
-/* This must be at least 17 for Europe/Samara and Europe/Vilnius.  */
+/* This must be at least 18 for Europe/Vilnius with 'zic -b fat'.  */
 # define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */
 #endif /* !defined TZ_MAX_TYPES */
 
 #ifndef TZ_MAX_CHARS
+/* This must be at least 40 for America/Anchorage.  */
 # define TZ_MAX_CHARS 50	/* Maximum number of abbreviation characters */
 				/* (limited by what unsigned chars can hold) */
 #endif /* !defined TZ_MAX_CHARS */
 
 #ifndef TZ_MAX_LEAPS
+/* This must be at least 27 for leap seconds from 1972 through mid-2023.
+   There's a plan to discontinue leap seconds by 2035.  */
 # define TZ_MAX_LEAPS 50	/* Maximum number of leap second corrections */
 #endif /* !defined TZ_MAX_LEAPS */