IANA 2022f

tz/Makefile

@@ -210,7 +210,8 @@ LDLIBS=
 #  -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_GETRANDOM if getgrandom works (e.g., GNU/Linux)*
+#  -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).
@@ -222,16 +223,17 @@ LDLIBS=
 #  -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_SETENV=0 if your system lacks the setenv function
 #  -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_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_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>
+#  -DHAVE_UNISTD_H=0 if your compiler lacks a <unistd.h>*
+#  -DHAVE_UTMPX_H=0 if your compiler lacks a <utmpx.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'.
@@ -254,14 +256,17 @@ LDLIBS=
 #	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".
+#	and bugs in some TZif readers, notably older ones that
+#	ignore or otherwise mishandle 64-bit data in TZif files;
+#	however, fat TZif files may trigger bugs in newer TZif readers.
+#	Slim TZif files are more efficient, and are the default.
 #  -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
+#
+# * Options marked "*" can be omitted if your compiler is C23 compatible.
+#
 # Select instrumentation via "make GCC_INSTRUMENT='whatever'".
 GCC_INSTRUMENT = \
   -fsanitize=undefined -fsanitize-address-use-after-scope \
@@ -397,8 +402,9 @@ 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.
+# To grow the files and work around bugs in older applications,
+# possibly at the expense of introducing bugs in newer ones,
+# append "-b fat"; see ZIC_BLOAT_DEFAULT above.
 # See the zic man page for more about -b and -r.
 ZFLAGS=
 
@@ -818,13 +824,19 @@ check_slashed_abbrs: $(TDATA_TO_CHECK)
 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 $$3}' backward | LC_ALL=C sort -cu
+		$(AWK) '/^Link/ {printf "%.5d %s\n", g, $$3} /^$$/ {g++}' \
+		  backward | LC_ALL=C sort -cu
 		$(AWK) '/^Zone/ {print $$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
+		$(AWK) \
+		  -v DATAFORM=$(DATAFORM) \
+		  -v backcheck=backward \
+		  -f checklinks.awk $(TDATA_TO_CHECK)
+		$(AWK) \
+		  -v DATAFORM=$(DATAFORM) \
+		  -f checklinks.awk tzdata.zi
 		touch $@
 
 check_tables:	checktab.awk $(YDATA) backward $(ZONETABLES)

tz/NEWS

@@ -1,5 +1,106 @@
 News for the tz database
 
+Release 2022f - 2022-10-28 18:04:57 -0700
+
+  Briefly:
+    Mexico will no longer observe DST except near the US border.
+    Chihuahua moves to year-round -06 on 2022-10-30.
+    Fiji no longer observes DST.
+    Move links to 'backward'.
+    In vanguard form, GMT is now a Zone and Etc/GMT a link.
+    zic now supports links to links, and vanguard form uses this.
+    Simplify four Ontario zones.
+    Fix a Y2438 bug when reading TZif data.
+    Enable 64-bit time_t on 32-bit glibc platforms.
+    Omit large-file support when no longer needed.
+    In C code, use some C23 features if available.
+    Remove no-longer-needed workaround for Qt bug 53071.
+
+  Changes to future timestamps.
+
+    Mexico will no longer observe DST after 2022, except for areas
+    near the US border that continue to observe US DST rules.
+    On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
+    from -07 (-06 with DST) to year-round -06, thus not changing
+    its clocks that day.  The new law states that Chihuahua
+    near the US border no longer observes US DST.
+
+    Fiji will not observe DST in 2022/3.  (Thanks to Shalvin Narayan.)
+    For now, assume DST is suspended indefinitely.
+
+  Changes to data
+
+    Move links to 'backward' to ease and simplify link maintenance.
+    This affects generated data only if you use 'make BACKWARD='.
+
+    GMT is now a Zone and Etc/GMT a link instead of vice versa,
+    as GMT is needed for leap second support whereas Etc/GMT is not.
+    However, this change exposes a bug in TZUpdater 2.3.2 so it is
+    present only in vanguard form for now.
+
+    Vanguard form now uses links to links, as zic now supports this.
+
+  Changes to past timestamps
+
+    Simplify four Ontario zones, as most of the post-1970 differences
+    seem to have been imaginary.  (Problem reported by Chris Walton.)
+    Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay
+    to 'backzone'; backward-compatibility links still work, albeit
+    with some different timestamps before November 2005.
+
+  Changes to code
+
+    zic now supports links to links regardless of input line order.
+    For example, if Australia/Sydney is a Zone, the lines
+      Link Australia/Canberra Australia/ACT
+      Link Australia/Sydney Australia/Canberra
+    now work correctly, even though the shell commands
+      ln Australia/Canberra Australia/ACT
+      ln Australia/Sydney Australia/Canberra
+    would fail because the first command attempts to use a link
+    Australia/Canberra that does not exist until after the second
+    command is executed.  Previously, zic had unspecified behavior if
+    a Link line's target was another link, and zic often misbehaved if
+    a Link line's target was a later Link line.
+
+    Fix line number in zic's diagnostic for a link to a link.
+
+    Fix a bug that caused localtime to mishandle timestamps starting
+    in the year 2438 when reading data generated by 'zic -b fat' when
+    distant-future DST transitions occur at times given in standard
+    time or in UT, not the usual case of local time.  This occurs when
+    the corresponding .zi Rule lines specify DST transitions with TO
+    columns of 'max' and AT columns that end in 's' or 'u'.  The
+    number 2438 comes from the 32-bit limit in the year 2038, plus the
+    400-year Gregorian cycle.  (Problem reported by Bradley White.)
+
+    On glibc 2.34 and later, which optionally supports 64-bit time_t
+    on platforms like x86 where time_t was traditionally 32 bits,
+    default time_t to 64 instead of 32 bits.  This lets functions like
+    localtime support timestamps after the year 2038, and fixes
+    year-2038 problems in zic when accessing files dated after 2038.
+    To continue to limit time_t to 32 bits on these platforms, use
+    "make CFLAGS='-D_TIME_BITS=32'".
+
+    In C code, do not enable large-file support on platforms like AIX
+    and macOS that no longer need it now that tzcode does not use
+    off_t or related functions like 'stat'.  Large-file support is
+    still enabled by default on GNU/Linux, as it is needed for 64-bit
+    time_t support.
+
+    In C code, prefer C23 keywords to pre-C23 macros for alignof,
+    bool, false, and true.  Also, use the following C23 features if
+    available: __has_include, unreachable.
+
+    zic no longer works around Qt bug 53071, as the relevant Qt
+    releases have been out of support since 2019.  This change affects
+    only fat TZif files, as thin files never had the workaround.
+
+    zdump no longer modifies the environ vector when compiled on
+    platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
+    This avoid undefined behavior on POSIX platforms.
+
+
 Release 2022e - 2022-10-11 11:13:02 -0700
 
   Briefly: