Update tzdata and zoneinfo to version 2024b.

Author: GitHub Actions

tzdata/CONTRIBUTING

@@ -23,10 +23,10 @@ such as renaming, adding or removing zones, please read
 "Theory and pragmatics of the tz code and data"
 <https://www.iana.org/time-zones/repository/theory.html>.
 It is also good to browse the mailing list archives
-<https://mm.icann.org/pipermail/tz/> for examples of patches that tend
-to work well.  Additions to data should contain commentary citing
-reliable sources as justification.  Citations should use "https:" URLs
-if available.
+<https://lists.iana.org/hyperkitty/list/[email protected]/>
+for examples of patches that tend to work well.
+Changes should contain commentary citing reliable sources.
+Citations should use "https:" URLs if available.
 
 For changes that fix sensitive security-related bugs, please see the
 distribution's 'SECURITY' file.
@@ -63,12 +63,16 @@ If you use Git the following workflow may be helpful:
   * Edit source files.  Include commentary that justifies the
     changes by citing reliable sources.
 
-  * Debug the changes, e.g.:
+  * Debug the changes locally, e.g.:
 
-        make check
-        make install
+        make TOPDIR=$PWD/tz clean check install
         ./zdump -v America/Los_Angeles
 
+    Although builds assume only basic POSIX, they use extra features
+    if available.  'make check' accesses validator.w3.org unless you
+    lack 'curl' or use 'make CURL=:'.  If you have the latest GCC,
+    "make CFLAGS='$(GCC_DEBUG_FLAGS)'" does extra checking.
+
   * For each separable change, commit it in the new branch, e.g.:
 
         git add northamerica

tzdata/Makefile

@@ -1,5 +1,125 @@
 News for the tz database
 
+Release 2024b - 2024-09-04 12:27:47 -0700
+
+  Briefly:
+    Improve historical data for Mexico, Mongolia, and Portugal.
+    System V names are now obsolescent.
+    The main data form now uses %z.
+    The code now conforms to RFC 8536 for early timestamps.
+    Support POSIX.1-2024, which removes asctime_r and ctime_r.
+    Assume POSIX.2-1992 or later for shell scripts.
+    SUPPORT_C89 now defaults to 1.
+
+  Changes to past timestamps
+
+    Asia/Choibalsan is now an alias for Asia/Ulaanbaatar rather than
+    being a separate Zone with differing behavior before April 2008.
+    This seems better given our wildly conflicting information about
+    Mongolia's time zone history.  (Thanks to Heitor David Pinto.)
+
+    Historical transitions for Mexico have been updated based on
+    official Mexican decrees.  The affected timestamps occur during
+    the years 1921-1927, 1931, 1945, 1949-1970, and 1981-1997.
+    The affected zones are America/Bahia_Banderas, America/Cancun,
+    America/Chihuahua, America/Ciudad_Juarez, America/Hermosillo,
+    America/Mazatlan, America/Merida, America/Mexico_City,
+    America/Monterrey, America/Ojinaga, and America/Tijuana.
+    (Thanks to Heitor David Pinto.)
+
+    Historical transitions for Portugal, represented by Europe/Lisbon,
+    Atlantic/Azores, and Atlantic/Madeira, have been updated based on a
+    close reading of old Portuguese legislation, replacing previous data
+    mainly originating from Whitman and Shanks & Pottenger.  These
+    changes affect a few transitions in 1917-1921, 1924, and 1940
+    throughout these regions by a few hours or days, and various
+    timestamps between 1977 and 1993 depending on the region.  In
+    particular, the Azores and Madeira did not observe DST from 1977 to
+    1981.  Additionally, the adoption of standard zonal time in former
+    Portuguese colonies have been adjusted: Africa/Maputo in 1909, and
+    Asia/Dili by 22 minutes at the start of 1912.
+    (Thanks to Tim Parenti.)
+
+  Changes to past tm_isdst flags
+
+    The period from 1966-04-03 through 1966-10-02 in Portugal is now
+    modeled as DST, to more closely reflect how contemporaneous changes
+    in law entered into force.
+
+  Changes to data
+
+    Names present only for compatibility with UNIX System V
+    (last released in the 1990s) have been moved to 'backward'.
+    These names, which for post-1970 timestamps mostly just duplicate
+    data of geographical names, were confusing downstream uses.
+    Names moved to 'backward' are now links to geographical names.
+    This affects behavior for TZ='EET' for some pre-1981 timestamps,
+    for TZ='CET' for some pre-1947 timestamps, and for TZ='WET' for
+    some pre-1996 timestamps.  Also, TZ='MET' now behaves like
+    TZ='CET' and so uses the abbreviation "CET" rather than "MET".
+    Those needing the previous TZDB behavior, which does not match any
+    real-world clocks, can find the old entries in 'backzone'.
+    (Problem reported by Justin Grant.)
+
+    The main source files' time zone abbreviations now use %z,
+    supported by zic since release 2015f and used in vanguard form
+    since release 2022b.  For example, America/Sao_Paulo now contains
+    the zone continuation line "-3:00 Brazil %z", which is less error
+    prone than the old "-3:00 Brazil -03/-02".  This does not change
+    the represented data: the generated TZif files are unchanged.
+    Rearguard form still avoids %z, to support obsolescent parsers.
+
+    Asia/Almaty has been removed from zonenow.tab as it now agrees
+    with Asia/Tashkent for future timestamps, due to Kazakhstan's
+    2024-02-29 time zone change.  Similarly, America/Scoresbysund
+    has been removed, as it now agrees with America/Nuuk due to
+    its 2024-03-31 time zone change.
+
+  Changes to code
+
+    localtime.c now always uses a TZif file's time type 0 to handle
+    timestamps before the file's first transition.  Formerly,
+    localtime.c sometimes inferred a different time type, in order to
+    handle problematic data generated by zic 2018e or earlier.  As it
+    is now safe to assume more recent versions of zic, there is no
+    longer a pressing need to fail to conform RFC 8536 section 3.2,
+    which requires using time type 0 in this situation.  This change
+    does not affect behavior when reading TZif files generated by zic
+    2018f and later.
+
+    POSIX.1-2024 removes asctime_r and ctime_r and does not let
+    libraries define them, so remove them except when needed to
+    conform to earlier POSIX.  These functions are dangerous as they
+    can overrun user buffers.  If you still need them, add
+    -DSUPPORT_POSIX2008 to CFLAGS.
+
+    The SUPPORT_C89 option now defaults to 1 instead of 0, fixing a
+    POSIX-conformance bug introduced in 2023a.
+
+    tzselect now supports POSIX.1-2024 proleptic TZ strings.  Also, it
+    assumes POSIX.2-1992 or later, as practical porting targets now
+    all support that, and it uses some features from POSIX.1-2024 if
+    available.
+
+  Changes to build procedure
+
+    'make check' no longer requires curl and Internet access.
+
+    The build procedure now assumes POSIX.2-1992 or later, to simplify
+    maintenance.  To build on Solaris 10, the only extant system still
+    defaulting to pre-POSIX, prepend /usr/xpg4/bin to PATH.
+
+  Changes to documentation
+
+    The documentation now reflects POSIX.1-2024.
+
+  Changes to commentary
+
+    Commentary about historical transitions in Portugal and her former
+    colonies has been expanded with links to many relevant legislation.
+    (Thanks to Tim Parenti.)
+
+
 Release 2024a - 2024-02-01 09:28:56 -0800
 
   Briefly:
@@ -161,7 +281,7 @@ Release 2023d - 2023-12-21 20:02:24 -0800
      * It uses the special .POSIX target.
      * It quotes special characters more carefully.
      * It no longer mishandles builds in an ISO 8859 locale.
-    Due to the CC changes, TZDIR is now #defined in a file tzfile.h
+    Due to the CC changes, TZDIR is now #defined in a file tzdir.h
     built by 'make', not in a $(CC) -D option.  Also, TZDEFAULT is
     now treated like TZDIR as they have similar roles.
 
@@ -283,7 +403,7 @@ Release 2023a - 2023-03-22 12:39:33 -0700
     To improve tzselect diagnostics, zone1970.tab's comments column is
     now limited to countries that have multiple timezones.
 
-    Note that leap seconds are planned to be discontinued by 2035.
+    Note that there are plans to discontinue leap seconds by 2035.
 
 
 Release 2022g - 2022-11-29 08:58:31 -0800

tzdata/NEWS

@@ -103,17 +103,16 @@ Zone	Africa/Algiers	0:12:12 -	LMT	1891 Mar 16
 
 # Cape Verde / Cabo Verde
 #
-# From Paul Eggert (2018-02-16):
-# Shanks gives 1907 for the transition to +02.
-# For now, ignore that and follow the 1911-05-26 Portuguese decree
-# (see Europe/Lisbon).
+# From Tim Parenti (2024-07-01), per Paul Eggert (2018-02-16):
+# For timestamps before independence, see commentary for Europe/Lisbon.
+# Shanks gives 1907 instead for the transition to -02.
 #
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone Atlantic/Cape_Verde -1:34:04 -	LMT	1912 Jan 01  2:00u # Praia
-			-2:00	-	-02	1942 Sep
-			-2:00	1:00	-01	1945 Oct 15
-			-2:00	-	-02	1975 Nov 25  2:00
-			-1:00	-	-01
+			-2:00	-	%z	1942 Sep
+			-2:00	1:00	%z	1945 Oct 15
+			-2:00	-	%z	1975 Nov 25  2:00
+			-1:00	-	%z
 
 # Chad
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -345,14 +344,12 @@ Zone	Africa/Cairo	2:05:09 -	LMT	1900 Oct
 
 # Guinea-Bissau
 #
-# From Paul Eggert (2018-02-16):
-# Shanks gives 1911-05-26 for the transition to WAT,
-# evidently confusing the date of the Portuguese decree
-# (see Europe/Lisbon) with the date that it took effect.
+# From Tim Parenti (2024-07-01), per Paul Eggert (2018-02-16):
+# For timestamps before independence, see commentary for Europe/Lisbon.
 #
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Bissau	-1:02:20 -	LMT	1912 Jan  1  1:00u
-			-1:00	-	-01	1975
+			-1:00	-	%z	1975
 			 0:00	-	GMT
 
 # Comoros
@@ -417,10 +414,10 @@ Zone	Africa/Bissau	-1:02:20 -	LMT	1912 Jan  1  1:00u
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Nairobi	2:27:16	-	LMT	1908 May
-			2:30	-	+0230	1928 Jun 30 24:00
+			2:30	-	%z	1928 Jun 30 24:00
 			3:00	-	EAT	1930 Jan  4 24:00
-			2:30	-	+0230	1936 Dec 31 24:00
-			2:45	-	+0245	1942 Jul 31 24:00
+			2:30	-	%z	1936 Dec 31 24:00
+			2:45	-	%z	1942 Jul 31 24:00
 			3:00	-	EAT
 
 # Liberia
@@ -591,7 +588,7 @@ Rule Mauritius	2008	only	-	Oct	lastSun	2:00	1:00	-
 Rule Mauritius	2009	only	-	Mar	lastSun	2:00	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
-			4:00 Mauritius	+04/+05
+			4:00 Mauritius	%z
 # Agalega Is, Rodriguez
 # no information; probably like Indian/Mauritius
 
@@ -1071,10 +1068,10 @@ Rule	Morocco	2087	only	-	May	11	 2:00	0	-
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone Africa/Casablanca	-0:30:20 -	LMT	1913 Oct 26
-			 0:00	Morocco	+00/+01	1984 Mar 16
-			 1:00	-	+01	1986
-			 0:00	Morocco	+00/+01	2018 Oct 28  3:00
-			 1:00	Morocco	+01/+00
+			 0:00	Morocco	%z	1984 Mar 16
+			 1:00	-	%z	1986
+			 0:00	Morocco	%z	2018 Oct 28  3:00
+			 1:00	Morocco	%z
 
 # Western Sahara
 #
@@ -1088,9 +1085,9 @@ Zone Africa/Casablanca	-0:30:20 -	LMT	1913 Oct 26
 # since most of it was then controlled by Morocco.
 
 Zone Africa/El_Aaiun	-0:52:48 -	LMT	1934 Jan # El Aaiún
-			-1:00	-	-01	1976 Apr 14
-			 0:00	Morocco	+00/+01	2018 Oct 28  3:00
-			 1:00	Morocco	+01/+00
+			-1:00	-	%z	1976 Apr 14
+			 0:00	Morocco	%z	2018 Oct 28  3:00
+			 1:00	Morocco	%z
 
 # Botswana
 # Burundi
@@ -1101,13 +1098,27 @@ Zone Africa/El_Aaiun	-0:52:48 -	LMT	1934 Jan # El Aaiún
 # Zambia
 # Zimbabwe
 #
-# Shanks gives 1903-03-01 for the transition to CAT.
-# Perhaps the 1911-05-26 Portuguese decree
-# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
-# merely made it official?
+# From Tim Parenti (2024-07-01):
+# For timestamps before Mozambique's independence, see commentary for
+# Europe/Lisbon.
+#
+# From Paul Eggert (2024-05-24):
+# The London Gazette, 1903-04-03, page 2245, says that
+# as of 1903-03-03 a time ball at the port of Lourenço Marques
+# (as Maputo was then called) was dropped daily at 13:00:00 LMT,
+# corresponding to 22:49:41.7 GMT, so local time was +02:10:18.3.
+# Conversely, the newspaper South Africa, 1909-02-09, page 321,
+# says the port had just installed an apparatus that communicated
+# "from the controlling clock in the new Observatory at Reuben Point ...
+# exact mean South African time, i.e., 30 deg., or 2 hours East of Greenwich".
+# Although Shanks gives 1903-03-01 for the transition to CAT,
+# evidently the port transitioned to CAT after 1903-03-03 but before
+# the Portuguese legal transition of 1912-01-01 (see Europe/Lisbon commentary).
+# For lack of better info, list 1909 as the transition date.
 #
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone	Africa/Maputo	2:10:20 -	LMT	1903 Mar
+		#STDOFF	2:10:18.3
+Zone	Africa/Maputo	2:10:18 -	LMT	1909
 			2:00	-	CAT
 
 # Namibia
@@ -1172,7 +1183,7 @@ Rule	Namibia	1995	2017	-	Apr	Sun>=1	2:00	-1:00	WAT
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Windhoek	1:08:24 -	LMT	1892 Feb 8
-			1:30	-	+0130	1903 Mar
+			1:30	-	%z	1903 Mar
 			2:00	-	SAST	1942 Sep 20  2:00
 			2:00	1:00	SAST	1943 Mar 21  2:00
 			2:00	-	SAST	1990 Mar 21 # independence
@@ -1260,7 +1271,7 @@ Zone	Africa/Windhoek	1:08:24 -	LMT	1892 Feb 8
 Zone	Africa/Lagos	0:13:35 -	LMT	1905 Jul  1
 			0:00	-	GMT	1908 Jul  1
 			0:13:35	-	LMT	1914 Jan  1
-			0:30	-	+0030	1919 Sep  1
+			0:30	-	%z	1919 Sep  1
 			1:00	-	WAT
 
 # São Tomé and Príncipe