Update zoneinfo to 2026a

Author: GitHub Actions

tzdata/Makefile

@@ -66,28 +66,6 @@ DATAFORM=		main
 
 LOCALTIME=	Factory
 
-# The POSIXRULES macro controls interpretation of POSIX-like TZ
-# settings like TZ='EET-2EEST' that lack DST transition rules.
-# 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-# Any other value for POSIXRULES is obsolete and should not be relied on, as: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.
-# 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 POSIXRULES is '-' or if the template file cannot be accessed.
-
 
 # Installation locations.
 #
@@ -170,7 +148,7 @@ TIME_T_ALTERNATIVES_TAIL = int_least32_t.ck uint_least32_t.ck \
 # 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
+REDO=		posix_only
 
 # Whether to put an "Expires" line in the leapseconds file.
 # Use EXPIRES_LINE=1 to put the line in, 0 to omit it.
@@ -284,7 +262,10 @@ LDLIBS=
 #  -DHAVE_STRDUP=0 if your system lacks the strdup function
 #  -DHAVE_STRNLEN=0 if your system lacks the strnlen function+
 #  -DHAVE_STRTOLL=0 if your system lacks the strtoll function+
-#  -DHAVE_STRUCT_STAT_ST_CTIM=0 if struct stat lacks a member st_ctim+
+#  -DHAVE_STRUCT_STAT_ST_CTIM=0 if struct stat lacks a status-change member
+#	of type struct timespec, so code should use st_ctime instead;
+#	but if the status-change member name is st_ctimespec,
+#	use -Dst_ctim=st_ctimespec instead (default is guessed)+
 #  -DHAVE_STRUCT_TIMESPEC=0 if your system lacks struct timespec+
 #  -DHAVE_SYMLINK=0 if your system lacks the symlink function
 #  -DHAVE_SYS_STAT_H=0 if <sys/stat.h> does not work*
@@ -322,13 +303,13 @@ LDLIBS=
 #		variable, 0 otherwise (default is guessed)
 #	      -DHAVE_SYS_SINGLE_THREADED_H=0 if <sys/single_threaded.h> works,
 #		0 otherwise (default is guessed)
-#	  -DTHREAD_RWLOCK to use read-write locks intead of mutexes.
-#	    This can improve paralellism and thus save real time
+#	  -DTHREAD_RWLOCK to use read-write locks instead of mutexes.
+#	    This can improve parallelism and thus save real time
 #	    if many threads call tzcode functions simultaneously.
 #	    It also costs CPU time and thus energy.
 #	  -DTHREAD_TM_MULTI to have gmtime, localtime, and offtime
 #	    return different struct tm * addresses in different threads.
-#	    This supports unportable programs that call
+#	    This supports nonportable programs that call
 #	    gmtime/localtime/offtime when they should call
 #	    gmtime_r/localtime_r/offtime_r to avoid races.
 #	    Because the corresponding storage is freed on thread exit,
@@ -347,10 +328,13 @@ LDLIBS=
 #  -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"
+#  -DTZ_RUNTIME_LEAPS=0 to disable runtime support for leap seconds.
+#	This conforms to POSIX, shrinks tzcode's attack surface,
+#	and is more efficient.  However, it fails to support Internet
+#	RFC 9636's leap seconds.
 #  -DTZDEFRULESTRING=\",date/time,date/time\" to default to the specified
-#	DST transitions for proleptic format TZ strings lacking them,
-#	in the usual case where POSIXRULES is '-'.  If not specified,
-#	TZDEFRULESTRING defaults to US rules for future DST transitions.
+#	DST transitions for proleptic format TZ strings lacking them.
+#	If not specified, it defaults to US rules for future DST transitions.
 #	This mishandles some past timestamps, as US DST rules have changed.
 #	It also mishandles settings like TZ='EET-2EEST' for eastern Europe,
 #	as Europe and US DST rules differ.
@@ -400,12 +384,13 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 \
   -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=cold \
   -Wsuggest-attribute=const -Wsuggest-attribute=format \
   -Wsuggest-attribute=malloc \
   -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \
   -Wtrampolines -Wundef -Wunused-macros -Wuse-after-free=3 \
   -Wvariadic-macros -Wvla -Wwrite-strings \
+  -Wzero-as-null-pointer-constant \
   -Wno-format-nonliteral -Wno-sign-compare -Wno-type-limits
 #
 # If your system has a "GMT offset" field in its "struct tm"s
@@ -723,7 +708,6 @@ install:	all $(DATA) $(REDO) $(MANS)
 			'$(DESTDIR)$(MANDIR)/man3' '$(DESTDIR)$(MANDIR)/man5' \
 			'$(DESTDIR)$(MANDIR)/man8'
 		$(ZIC_INSTALL) -l $(LOCALTIME) \
-			-p $(POSIXRULES) \
 			-t '$(DESTDIR)$(TZDEFAULT)'
 		cp -f $(TABDATA) '$(DESTDIR)$(TZDIR)/.'
 		cp tzselect '$(DESTDIR)$(BINDIR)/.'

tzdata/NEWS

@@ -1,5 +1,100 @@
 News for the tz database
 
+Release 2026a - 2026-03-01 22:59:49 -0800
+
+  Briefly:
+    Moldova has used EU transition times since 2022.
+    The "right" TZif files are no longer installed by default.
+    -DTZ_RUNTIME_LEAPS=0 disables runtime support for leap seconds.
+    TZif files are no longer limited to 50 bytes of abbreviations.
+    zic is no longer limited to 50 leap seconds.
+    Several integer overflow bugs have been fixed.
+
+  Changes to past and future timestamps
+
+    Since 2022 Moldova has observed EU transition times, that is, it
+    has sprung forward at 03:00, not 02:00, and has fallen back at
+    04:00, not 03:00.  (Thanks to Heitor David Pinto.)
+
+  Changes to data
+
+    Remove Europe/Chisinau from zonenow.tab, as it now agrees with
+    Europe/Athens for future timestamps.
+
+  Changes to build procedure
+
+    The Makefile no longer by default installs an alternate set
+    of TZif files for system clocks that count leap seconds.
+    Install with 'make REDO=posix_right' to get the old default,
+    which is rarely used in major downstream distributions.
+    If your system clock counts leap seconds (contrary to POSIX),
+    it is better to install with 'make REDO=right_only'.
+    This change does not affect the leapseconds file, which is still
+    installed as before.
+
+    The Makefile's POSIXRULES option, which was declared obsolete in
+    release 2019b, has been removed.  The Makefile's build procedure
+    thus no longer optionally installs the obsolete posixrules file.
+
+  Changes to code
+
+    Compiling with the new option -DTZ_RUNTIME_LEAPS=0 disables
+    runtime support for leap seconds.  Although this conforms to
+    POSIX, shrinks tzcode's attack surface, and is more efficient,
+    it fails to support Internet RFC 9636's leap seconds.
+
+    zic now can generate, and localtime.c can now use, TZif files that
+    hold up to 256 bytes of abbreviations, counting trailing NULs.
+    The previous limit was 50 bytes, and some tzdata TZif files were
+    already consuming 40 bytes.  zic -v warns if it generates a file
+    that exceeds the old 50-byte limit.
+
+    zic -L can now generate TZif files with more than 50 leap seconds.
+    This helps test TZif readers not limited to 50 leap seconds, as
+    tzcode's localtime.c is; it has little immediate need for
+    practical timekeeping as there have been only 27 leap seconds and
+    possibly there will be no more, due to planned changes to UTC.
+    zic -v warns if its output exceeds the old 50-second limit.
+
+    localtime.c no longer accesses the posixrules file generated by
+    zic -p.  Hence for obsolete and nonconforming settings like
+    TZ="AST4ADT" it now typically falls back on US DST rules, rather
+    than attempting to override this fallback with the contents of the
+    posixrules file.  This removes library support that was declared
+    obsolete in release 2019b, and fixes some undefined behavior.
+    (Undefined behavior reported by GitHub user Naveed8951.)
+
+    The posix2time, posix2time_z, time2posix, and time2posix_z
+    functions now set errno=EOVERFLOW and return ((time_t) -1) if the
+    result is not representable.  Formerly they had undefined behavior
+    that could in practice result in crashing, looping indefinitely,
+    or returning an incorrect result.  As before, these functions are
+    defined only when localtime.c is compiled with the -DSTD_INSPIRED
+    option.
+
+    Some other undefined behavior, triggered by TZif files containing
+    outlandish but conforming UT offsets or leap second corrections,
+    has also been fixed.  (Some of these bugs reported by Naveed8951.)
+
+    localtime.c no longer rejects TZif files that exactly fit in its
+    internal structures, fixing off-by-one typos introduced in 2014g.
+
+    zic no longer generates a no-op transition when
+    simultaneous Rule and Zone changes cancel each other out.
+    This occurs in tzdata only in Asia/Tbilisi on 1997-03-30.
+    (Thanks to Renchunhui for a test case showing the bug.)
+
+    zic no longer assumes you can fflush a read-only stream.
+    (Problem reported by Christos Zoulas.)
+
+    zic no longer generates UT offsets equal to -2**31 and localtime.c
+    no longer accepts them, as they can cause trouble in both
+    localtime.c and its callers.  RFC 9636 prohibits such offsets.
+
+    zic -p now warns that the -p option is obsolete and likely
+    ineffective.
+
+
 Release 2025c - 2025-12-10 14:42:37 -0800
 
   Briefly:
@@ -69,6 +164,8 @@ Release 2025c - 2025-12-10 14:42:37 -0800
     The new CFLAGS options -DHAVE_STRUCT_STAT_ST_CTIM=0 and
     -DHAVE_STRUCT_TIMESPEC=0 port to non-POSIX.1-2008 platforms
     that lack st_ctim and struct timespec, respectively.
+    On these platforms, the code falls back on st_ctime to
+    implement -DTZ_CHANGE_INTERVAL=N.
 
     tzset etc. now treat ' ' like '_' in time zone abbreviations,
     just as they treat other invalid bytes.  This continues the
@@ -89,7 +186,7 @@ Release 2025c - 2025-12-10 14:42:37 -0800
 
     The new CFLAGS option -TTHREAD_TM_MULTI causes localtime to return
     a pointer to thread-specific memory, as FreeBSD does, instead of
-    to the same memory in all threads.  This supports unportable
+    to the same memory in all threads.  This supports nonportable
     programs that incorrectly use localtime instead of localtime_r.
     This option affects gmtime and offtime similarly to localtime.
     Because the corresponding storage is freed on thread exit, this

tzdata/backzone

@@ -1757,13 +1757,12 @@ Zone Pacific/Majuro	 11:24:48 -	LMT	1901
 # Midway
 #
 # From Mark Brader (2005-01-23):
-# [Fallacies and Fantasies of Air Transport History, by R.E.G. Davies,
-# published 1994 by Paladwr Press, McLean, VA, USA; ISBN 0-9626483-5-3]
+# [<https://www.timetableimages.com/ttimages/pa/pa36/pa36.pdf>]
 # reproduced a Pan American Airways timetable from 1936, for their weekly
 # "Orient Express" flights between San Francisco and Manila, and connecting
 # flights to Chicago and the US East Coast.  As it uses some time zone
 # designations that I've never seen before:....
-# Fri. 6:30A Lv. HONOLOLU (Pearl Harbor), H.I.   H.L.T. Ar. 5:30P Sun.
+# Fri. 6:30A Lv. HONOLULU (Pearl Harbor), H.I. . H.L.T. Ar. 5:30P Sun.
 #  "   3:00P Ar. MIDWAY ISLAND . . . . . . . . . M.L.T. Lv. 6:00A  "
 #
 Zone Pacific/Midway	-11:49:28 -	LMT	1901

tzdata/etcetera

@@ -20,7 +20,8 @@
 # which load the "UTC" file to handle seconds properly.
 Zone	Etc/UTC		0	-	UTC
 
-# Functions like gmtime load the "GMT" file to handle leap seconds properly.
+# If leap second support is enabled, functions like gmtime
+# load the "GMT" file to handle leap seconds properly.
 # Vanguard section, which works with most .zi parsers.
 #Zone	GMT		0	-	GMT
 # Rearguard section, for TZUpdater 2.3.2 and earlier.

tzdata/europe

@@ -1041,9 +1041,19 @@ Zone Atlantic/Faroe	-0:27:04 -	LMT	1908 Jan 11 # Tórshavn
 
 # Greenland
 #
-# From Paul Eggert (2004-10-31):
+# From Paul Eggert (2026-01-22):
+# During World War II, Greenland was effectively independent of Denmark and
+# observed daylight saving time.  TIME, volume 37, page 23 (1941-04-21)
+# <https://time.com/archive/6770243/war-peace-greenlands-icy-mountains/> says,
+# "Penfield and West made their way to the U.S.'s most northerly consulate.
+# They were astonished to find that Greenlanders, with almost 24 hours of
+# sunlight a day during the summer, have daylight saving time."
+# As the details are unknown they are omitted from the data for now.
+#
 # During World War II, Germany maintained secret manned weather stations in
 # East Greenland and Franz Josef Land, but we don't know their time zones.
+# Also, they're likely out of scope for the database
+# as we lack resources to track every bit of military activity.
 # My source for this is Wilhelm Dege's book mentioned under Svalbard.
 #
 # From Paul Eggert (2017-12-10):
@@ -1957,7 +1967,6 @@ Zone	Europe/Malta	0:58:04 -	LMT	1893 Nov  2 # Valletta
 
 # From Stepan Golosunov (2016-03-07):
 # the act of the government of the Republic of Moldova Nr. 132 from 1990-05-04
-# http://lex.justice.md/viewdoc.php?action=view&view=doc&id=298782&lang=2
 # ... says that since 1990-05-06 on the territory of the Moldavian SSR
 # time would be calculated as the standard time of the second time belt
 # plus one hour of the "summer" time. To implement that clocks would be
@@ -2012,9 +2021,61 @@ Zone	Europe/Malta	0:58:04 -	LMT	1893 Nov  2 # Valletta
 # says the 2014-03-30 spring-forward transition was at 02:00 local time.
 # Guess that since 1997 Moldova has switched one hour before the EU.
 
+# From Heitor David Pinto (2026-02-22):
+# Soviet Moldovan resolution 132 of 1990 defined the summer time period from
+# the last Sunday in March at 2:00 to the last Sunday in September at 3:00,
+# matching the dates used in most of Europe at the time:
+# https://web.archive.org/web/20211107050832/http://lex.justice.md/viewdoc.php?action=view&view=doc&id=298782&lang=1
+#
+# It seems that in 1996 Moldova changed the end date to October like most of
+# Europe, but kept the transitions at 2:00 and 3:00 rather than 1:00 UTC,
+# which would have been locally 3:00 and 4:00....
+#
+# The notices in the Moldovan government website and broadcaster showed the
+# transitions at 2:00 and 3:00 until 2021:
+# 2015 https://old.gov.md/en/node/7304
+# 2016 https://old.gov.md/en/node/12587
+# 2017 https://old.gov.md/en/node/20654
+# 2017 https://old.gov.md/en/content/moldova-upholds-winter-time-night-28-29-october
+# 2018 https://old.gov.md/en/content/moldova-switch-summer-time
+# 2018 https://old.gov.md/en/content/cabinet-ministers-informs-about-switch-winter-time-28-october
+# 2019 https://old.gov.md/en/content/moldova-switch-summer-time-31-march
+# 2019 https://old.gov.md/en/node/31122
+# 2020 https://old.gov.md/en/node/32771
+# 2020 https://old.gov.md/en/node/34497
+# 2021 https://trm.md/ro/social/moldova-trece-in-aceasta-noapte-la-ora-de-vara
+# 2021 https://trm.md/en/social/republica-moldova-trece-la-ora-de-iarna1
+#
+# However, since 2022, the notices showed the transitions at 3:00 and 4:00,
+# matching the EU rule at 1:00 UTC:
+# 2022 https://trm.md/en/social/in-acest-weekend-republica-moldova-trece-la-ora-de-vara
+# 2022 https://old.gov.md/en/content/moldova-switch-winter-time
+# 2023 https://moldova1.md/p/6587/ora-de-vara-2023-cum-schimbam-acele-ceasornicelor-si-cand-trecem-la-ora-de-vara
+# 2023 https://old.gov.md/en/node/46662
+# 2024 https://moldova1.md/p/26535/republica-moldova-trece-la-ora-de-vara-in-acest-weekend
+# 2024 https://moldova1.md/p/37768/republica-moldova-trece-in-aceasta-noapte-la-ora-de-iarna
+# 2025 https://moldova1.md/p/46349/republica-moldova-trece-la-ora-de-vara-pe-30-martie-cum-ne-afecteaza-si-ce-recomanda-medicii
+# 2025 https://moldova1.md/p/60469/republica-moldova-trece-la-ora-de-iarna-ceasurile-se-dau-inapoi-cu-o-ora
+#
+# It seems that the changes to the end date and transition times were just
+# done in practice without formally changing the resolution. In late 2025, the
+# government said that the Soviet resolution was still in force, and proposed
+# a new resolution to replace it and formally establish the EU rule:
+# ... based on the notices, it seems that in practice Moldova already
+# uses the EU rule since 2022. This was also the year when Moldova applied to
+# join the EU.
+#
+# From Robert Bastian (2026-02-26):
+# This has been approved and published in the government gazette:
+# https://monitorul.gov.md/ro/monitorul/view/pdf/3234/part/2#page=27
+#
+# From Paul Eggert (2026-02-24):
+# Also see Svetlana Rudenko, "Moldova abandons the 'Soviet era'", Logos Press,
+# 2026-02-21 <https://logos-pres.md/en/news/moldova-abandons-the-soviet-era/>.
+
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
-Rule	Moldova	1997	max	-	Mar	lastSun	 2:00	1:00	S
-Rule	Moldova	1997	max	-	Oct	lastSun	 3:00	0	-
+Rule	Moldova	1997	2021	-	Mar	lastSun	 2:00	1:00	S
+Rule	Moldova	1997	2021	-	Oct	lastSun	 3:00	0	-
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Europe/Chisinau	1:55:20 -	LMT	1880
@@ -2027,7 +2088,8 @@ Zone	Europe/Chisinau	1:55:20 -	LMT	1880
 			2:00	Russia	EE%sT	1992
 			2:00	E-Eur	EE%sT	1997
 # See Romania commentary for the guessed 1997 transition to EU rules.
-			2:00	Moldova	EE%sT
+			2:00	Moldova	EE%sT	2022
+			2:00	EU	EE%sT
 
 # Poland
 
@@ -2413,7 +2475,7 @@ Zone Atlantic/Madeira	-1:07:36 -	LMT	1884        # Funchal
 # Nine O'clock <http://www.nineoclock.ro/POL/1778pol.html>
 # (1998-10-23) reports that the switch occurred at
 # 04:00 local time in fall 1998.  For lack of better info,
-# assume that Romania and Moldova switched to EU rules in 1997,
+# assume that Romania switched to EU rules in 1997,
 # the same year as Bulgaria.
 #
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S

tzdata/leap-seconds.list

@@ -60,15 +60,15 @@
 #
 #	The following line shows the last update of this file in NTP timestamp:
 #
-#$	3960835200
+#$	3976686858
 #
 #	2) Expiration date of the file given on a semi-annual basis: last June or last December
 #
-#	File expires on 28 June 2026
+#	File expires on 28 December 2026
 #
 #	Expire date in NTP timestamp:
 #
-#@	3991593600
+#@	4007404800
 #
 #
 #	LIST OF LEAP SECONDS
@@ -117,4 +117,4 @@
 #	please see the readme file in the 'source' directory :
 #	https://hpiers.obspm.fr/iers/bul/bulc/ntp/sources/README
 #
-#h	49db2447 571e5e1b 2f002a53 9c8da8e4 39b8e49e
+#h	2e101270 4e6749f8 2f1792b7 14a0c188 36bb19d6