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1981/2 Singapore+Malaysia switch from GMT+0730 to GMT+0800
by Robert Elz Dec. 1, 2022

Dec. 1, 2022

This press release was discovered, and brought up in another forum by Geoff Clare. It conflicts with the data in the Asia/Singapore and Asia/Kuala-Lumpur zones. https://corporate.nas.gov.sg/media/collections-and-research/time-zone-adjus… That puts the change as being from 23:29:59 Dec 31, 1981 -> 00:00:00 Jan 1, 1982 whereas tzdata (going back to quite ancient versions) has the transition 23:59:59 Dec 31, 1981 -> 00:30:00 Jan 1, 1982 The version from the web page makes more sense to me (as in that is how I would have done that transition) but that does not mean that it is necessarily correct. Nothing there shows a copy of the actual gazette notification by the President (of Singapore in that case, but I think we can safely assume that it was done the same as in Malaysia) which would be the actual specification, but that 2015 press release says it happened as described that it would happen in the 1981 press release which is included there. The "asia" file just says of this transition: 7:30 - +0730 1982 Jan 1 8:00 - +08 which is correct in a sense for either version of when the transition occurred, and perhaps raises a general question of when a step forward takes place at the boundary between two days, does it more often delete the last part of the previous day or the first part of the next? I can find nothing in my tz list archives that says anything at all about this transition - the earliest message with any specific content about Singapore I could see was a Jan 2004 message from Mok Ly Yng (forwarded to the list by ado@), but that's really about earlier transitions - this one was already in the data (just with SGT instead of +0730 and +08). There's also a long Sept 2014 discussion about a zdump bug that this particular transition, as defined by zic, revealed, and a shorter discussion about the SGT removal in Sept 2018 - but that's all I managed to find about Singapore. While not about the Singapore/Malaysia zones themselves, even older data that appears on the list (ie: looking at diffs patches, and updated zone files) shows that in 1996 this transition was believed to have happened in May 1982 (which seems to be from Shanks). That altered in Dec 2003, in a change described as: * Fix several Malaysia and Singapore entries before 1983. Among other things, they enjoyed 20-minute DST from 1933 to 1936, and we have more-accurate dates for WWII transitions. (Thanks to Mok Ly Yng for this info.) which notably does not mention the change moving from May 1982 -> 1 Jan 1982 but that change was made in that version. Nothing appears to have happened since. I suspect it would be correct to change the first of those lines to be 7:30 - +0730 23:30 1981 Dec 30 but I am no authority on that. kre

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[PROPOSED] Fix C23-related conformance bug
by Paul Eggert Dec. 1, 2022

Dec. 1, 2022

Problem reported by Houge Langley for ‘gcc -std=gnu99’ in: https://bugs.gentoo.org/show_bug.cgi?id=883719 * NEWS: Mention this. * date.c, localtime.c, private.h, zdump.c, zic.c: Use ATTRIBUTE_* at the start of function declarations, not later (such as after the keyword ‘static’). This is required for strict conformance to C23. --- NEWS | 6 ++++++ date.c | 2 +- localtime.c | 4 ++-- private.h | 6 +++--- zdump.c | 12 ++++++------ zic.c | 34 +++++++++++++++++----------------- 6 files changed, 35 insertions(+), 29 deletions(-) diff --git a/NEWS b/NEWS index 9cb175e7..25dcc875 100644 --- a/NEWS +++ b/NEWS @@ -4,6 +4,7 @@ Unreleased, experimental changes Briefly: tzcode no longer supports C89 unless built with -DSUPPORT_C89 + Fix use of C23 attributes. Changes to code @@ -12,6 +13,11 @@ Unreleased, experimental changes that is planned to be removed in a near-future version, when C99 or later will be required. + On C23-compatible platforms tzcode no longer uses syntax like + 'static [[noreturn]] void usage(void);'. Instead, it uses + '[[noreturn]] static void usage(void);' as strict C23 requires. + (Problem reported by Houge Langley.) + Release 2022g - 2022-11-29 08:58:31 -0800 diff --git a/date.c b/date.c index 11c5e5fe..97df6ab0 100644 --- a/date.c +++ b/date.c @@ -42,7 +42,7 @@ static void display(const char *, time_t); static void dogmt(void); static void errensure(void); static void timeout(FILE *, const char *, const struct tm *); -static ATTRIBUTE_NORETURN void usage(void); +ATTRIBUTE_NORETURN static void usage(void); int main(const int argc, char *argv[]) diff --git a/localtime.c b/localtime.c index f8a0a6eb..f1a8598b 100644 --- a/localtime.c +++ b/localtime.c @@ -843,7 +843,7 @@ is_digit(char c) ** Return a pointer to that character. */ -static ATTRIBUTE_REPRODUCIBLE const char * +ATTRIBUTE_REPRODUCIBLE static const char * getzname(register const char *strp) { register char c; @@ -864,7 +864,7 @@ getzname(register const char *strp) ** We don't do any checking here; checking is done later in common-case code. */ -static ATTRIBUTE_REPRODUCIBLE const char * +ATTRIBUTE_REPRODUCIBLE static const char * getqzname(register const char *strp, const int delim) { register int c; diff --git a/private.h b/private.h index c22354ac..999c1648 100644 --- a/private.h +++ b/private.h @@ -646,7 +646,7 @@ DEPRECATED_IN_C23 char *asctime(struct tm const *); char *asctime_r(struct tm const *restrict, char *restrict); DEPRECATED_IN_C23 char *ctime(time_t const *); char *ctime_r(time_t const *, char *); -double difftime(time_t, time_t) ATTRIBUTE_UNSEQUENCED; +ATTRIBUTE_UNSEQUENCED double difftime(time_t, time_t); size_t strftime(char *restrict, size_t, char const *restrict, struct tm const *restrict); # if HAVE_STRFTIME_L @@ -765,10 +765,10 @@ timezone_t tzalloc(char const *); void tzfree(timezone_t); # if STD_INSPIRED # if TZ_TIME_T || !defined posix2time_z -time_t posix2time_z(timezone_t, time_t) ATTRIBUTE_REPRODUCIBLE; +ATTRIBUTE_REPRODUCIBLE time_t posix2time_z(timezone_t, time_t); # endif # if TZ_TIME_T || !defined time2posix_z -time_t time2posix_z(timezone_t, time_t) ATTRIBUTE_REPRODUCIBLE; +ATTRIBUTE_REPRODUCIBLE time_t time2posix_z(timezone_t, time_t); # endif # endif #endif diff --git a/zdump.c b/zdump.c index 04953dcf..bac4a67a 100644 --- a/zdump.c +++ b/zdump.c @@ -89,7 +89,7 @@ static bool warned; static bool errout; static char const *abbr(struct tm const *); -static intmax_t delta(struct tm *, struct tm *) ATTRIBUTE_REPRODUCIBLE; +ATTRIBUTE_REPRODUCIBLE static intmax_t delta(struct tm *, struct tm *); static void dumptime(struct tm const *); static time_t hunt(timezone_t, time_t, time_t, bool); static void show(timezone_t, char *, time_t, bool); @@ -97,7 +97,7 @@ static void showextrema(timezone_t, char *, time_t, struct tm *, time_t); static void showtrans(char const *, struct tm const *, time_t, char const *, char const *); static const char *tformat(void); -static time_t yeartot(intmax_t) ATTRIBUTE_REPRODUCIBLE; +ATTRIBUTE_REPRODUCIBLE static time_t yeartot(intmax_t); /* Is C an ASCII digit? */ static bool @@ -125,7 +125,7 @@ is_alpha(char a) } } -static ATTRIBUTE_NORETURN void +ATTRIBUTE_NORETURN static void size_overflow(void) { fprintf(stderr, _("%s: size overflow\n"), progname); @@ -134,7 +134,7 @@ size_overflow(void) /* Return A + B, exiting if the result would overflow either ptrdiff_t or size_t. */ -static ATTRIBUTE_REPRODUCIBLE ptrdiff_t +ATTRIBUTE_REPRODUCIBLE static ptrdiff_t sumsize(size_t a, size_t b) { #ifdef ckd_add @@ -151,7 +151,7 @@ sumsize(size_t a, size_t b) /* Return a pointer to a newly allocated buffer of size SIZE, exiting on failure. SIZE should be nonzero. */ -static void * ATTRIBUTE_MALLOC +ATTRIBUTE_MALLOC static void * xmalloc(size_t size) { void *p = malloc(size); @@ -916,7 +916,7 @@ showextrema(timezone_t tz, char *zone, time_t lo, struct tm *lotmp, time_t hi) # include <stdarg.h> /* A substitute for snprintf that is good enough for zdump. */ -static int ATTRIBUTE_FORMAT((printf, 3, 4)) +ATTRIBUTE_FORMAT((printf, 3, 4)) static int my_snprintf(char *s, size_t size, char const *format, ...) { int n; diff --git a/zic.c b/zic.c index 892414af..f143fcef 100644 --- a/zic.c +++ b/zic.c @@ -459,20 +459,20 @@ static char roll[TZ_MAX_LEAPS]; ** Memory allocation. */ -static ATTRIBUTE_NORETURN void +ATTRIBUTE_NORETURN static void memory_exhausted(const char *msg) { fprintf(stderr, _("%s: Memory exhausted: %s\n"), progname, msg); exit(EXIT_FAILURE); } -static ATTRIBUTE_NORETURN void +ATTRIBUTE_NORETURN static void size_overflow(void) { memory_exhausted(_("size overflow")); } -static ATTRIBUTE_REPRODUCIBLE ptrdiff_t +ATTRIBUTE_REPRODUCIBLE static ptrdiff_t size_sum(size_t a, size_t b) { #ifdef ckd_add @@ -487,7 +487,7 @@ size_sum(size_t a, size_t b) size_overflow(); } -static ATTRIBUTE_REPRODUCIBLE ptrdiff_t +ATTRIBUTE_REPRODUCIBLE static ptrdiff_t size_product(ptrdiff_t nitems, ptrdiff_t itemsize) { #ifdef ckd_mul @@ -502,7 +502,7 @@ size_product(ptrdiff_t nitems, ptrdiff_t itemsize) size_overflow(); } -static ATTRIBUTE_REPRODUCIBLE ptrdiff_t +ATTRIBUTE_REPRODUCIBLE static ptrdiff_t align_to(ptrdiff_t size, ptrdiff_t alignment) { ptrdiff_t lo_bits = alignment - 1, sum = size_sum(size, lo_bits); @@ -526,7 +526,7 @@ memcheck(void *ptr) return ptr; } -static void * ATTRIBUTE_MALLOC +ATTRIBUTE_MALLOC static void * emalloc(size_t size) { return memcheck(malloc(size)); @@ -538,7 +538,7 @@ erealloc(void *ptr, size_t size) return memcheck(realloc(ptr, size)); } -static char * ATTRIBUTE_MALLOC +ATTRIBUTE_MALLOC static char * estrdup(char const *str) { return memcheck(strdup(str)); @@ -608,7 +608,7 @@ eat(int fnum, lineno num) eats(fnum, num, 0, -1); } -static void ATTRIBUTE_FORMAT((printf, 1, 0)) +ATTRIBUTE_FORMAT((printf, 1, 0)) static void verror(const char *const string, va_list args) { /* @@ -626,7 +626,7 @@ verror(const char *const string, va_list args) fprintf(stderr, "\n"); } -static void ATTRIBUTE_FORMAT((printf, 1, 2)) +ATTRIBUTE_FORMAT((printf, 1, 2)) static void error(const char *const string, ...) { va_list args; @@ -636,7 +636,7 @@ error(const char *const string, ...) errors = true; } -static void ATTRIBUTE_FORMAT((printf, 1, 2)) +ATTRIBUTE_FORMAT((printf, 1, 2)) static void warning(const char *const string, ...) { va_list args; @@ -666,7 +666,7 @@ close_file(FILE *stream, char const *dir, char const *name, } } -static ATTRIBUTE_NORETURN void +ATTRIBUTE_NORETURN static void usage(FILE *stream, int status) { fprintf(stream, @@ -3597,7 +3597,7 @@ lowerit(char a) } /* case-insensitive equality */ -static ATTRIBUTE_REPRODUCIBLE bool +ATTRIBUTE_REPRODUCIBLE static bool ciequal(register const char *ap, register const char *bp) { while (lowerit(*ap) == lowerit(*bp++)) @@ -3606,7 +3606,7 @@ ciequal(register const char *ap, register const char *bp) return false; } -static ATTRIBUTE_REPRODUCIBLE bool +ATTRIBUTE_REPRODUCIBLE static bool itsabbr(register const char *abbr, register const char *word) { if (lowerit(*abbr) != lowerit(*word)) @@ -3622,7 +3622,7 @@ itsabbr(register const char *abbr, register const char *word) /* Return true if ABBR is an initial prefix of WORD, ignoring ASCII case. */ -static ATTRIBUTE_REPRODUCIBLE bool +ATTRIBUTE_REPRODUCIBLE static bool ciprefix(char const *abbr, char const *word) { do @@ -3725,14 +3725,14 @@ getfields(char *cp, char **array, int arrayelts) return nsubs; } -static ATTRIBUTE_NORETURN void +ATTRIBUTE_NORETURN static void time_overflow(void) { error(_("time overflow")); exit(EXIT_FAILURE); } -static ATTRIBUTE_REPRODUCIBLE zic_t +ATTRIBUTE_REPRODUCIBLE static zic_t oadd(zic_t t1, zic_t t2) { #ifdef ckd_add @@ -3746,7 +3746,7 @@ oadd(zic_t t1, zic_t t2) time_overflow(); } -static ATTRIBUTE_REPRODUCIBLE zic_t +ATTRIBUTE_REPRODUCIBLE static zic_t tadd(zic_t t1, zic_t t2) { #ifdef ckd_add -- 2.37.2

2 1

[PROPOSED] Simplify zdump average-taking
by Paul Eggert Dec. 1, 2022

Dec. 1, 2022

* zdump.c (hunt): Simplify slightly, so that one more instruction can be int width rather than time_t width if that’s what the compiler prefers. No need to mention C89 in the comment, as C89 support is going away soon. (The code still happens to work in C89, for what it’s worth.) --- zdump.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/zdump.c b/zdump.c index a020102..04953dc 100644 --- a/zdump.c +++ b/zdump.c @@ -732,13 +732,9 @@ hunt(timezone_t tz, time_t lot, time_t hit, bool only_ok) for ( ; ; ) { /* T = average of LOT and HIT, rounding down. - Avoid overflow, even on oddball C89 platforms - where / rounds down and TIME_T_MIN == -TIME_T_MAX - so lot / 2 + hit / 2 might overflow. */ - time_t t = (lot / 2 - - ((lot % 2 + hit % 2) < 0) - + ((lot % 2 + hit % 2) == 2) - + hit / 2); + Avoid overflow. */ + int rem_sum = lot % 2 + hit % 2; + time_t t = (rem_sum == 2) - (rem_sum < 0) + lot / 2 + hit / 2; if (t == lot) break; tm_ok = my_localtime_rz(tz, &t, &tm) != NULL; -- 2.38.1

3 5

Re: [tz] New change in Mexico
by Brian Inglis Nov. 30, 2022

Nov. 30, 2022

On 2022-11-29 22:37, Tim Parenti wrote: > On Tue, 29 Nov 2022 at 13:29, Paul Eggert wrote: > I expect I didn't recognize > that as including Ciudad Juárez as opposed to one of the plain Juárezes > which also exist in Mexico. > On Tue, 29 Nov 2022 at 19:50, Heitor David Pinto wrote: > The municipalities have well-defined boundaries, see this map: > https://cuentame.inegi.org.mx/mapas/pdf/entidades/div_municipal/chihmpios.p… > Ah, that seems to be part of the issue — while the word "municipality" is often > used to refer to an individual settlement in US English, a "municipio" in Mexico > (and similar words in many other countries) is a second-level administrative > division, which is more akin to, say, a county in much of the US or a civil > parish in much of Britain. That is, these lists are not of individual > settlements which are far apart (although they often share names with such), but > rather of well-defined regions — administrative subdivisions of states — which, > as Heitor points out, cover the entire border. > https://en.wikipedia.org/wiki/Municipio <https://en.wikipedia.org/wiki/Municipio> > https://en.wikipedia.org/wiki/Municipalities_of_Mexico > <https://en.wikipedia.org/wiki/Municipalities_of_Mexico> > While "municipio" does, admittedly, seem to be best translated to English as > "municipality", since the English word has many meanings, it's maybe best to be > more faithful to the original Spanish use here for clarity. We've left > "municipio" untranslated in nearby commentary for Mexico before, so I've applied > the attached to the development repository to hopefully alleviate some further > confusion for others who might come to these comments unaware of some of the > details of Mexico's political subdivisions. While I don't necessarily expect > many more one-off adjustments to the new arrangement in the immediate future, if > that does come to pass, it might behoove us to further standardize our > commentary for the various Mexican zones (in a similar manner as was done for > the many Russian zones in 2014). > Anyway, that puts the dividing line between the two resultant zones along the > border between the municipio of Guadalupe to the northwest and the municipios of > Coyame del Sotol and Ojinaga to the southeast …which meets the US border between > Barrio Alto and Presidio de Pilares, about 15 km south-southeast of my > (comparatively uninformed) guess, which I suppose wasn't all too bad for a > ~900-km-long border. Same in most European countries and Canadian provinces: https://en.wikipedia.org/wiki/Local_government_in_Canada#Regional_municipal… "Depending on the province, this second tier may be called a county, regional municipality, regional district or regional county municipality." There are also some district, island, mountain resort, resort, rural, and specialized municipalities, each of which may have varying geographic extents as an administrative chunk of a province. -- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada La perfection est atteinte Perfection is achieved non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut -- Antoine de Saint-Exupéry

1 0

[PROPOSED 1/4] Always define STD_INSPIRED
by Paul Eggert Nov. 30, 2022

Nov. 30, 2022

* private.h (STD_INSPIRED): Default to 0. All uses changed. This is purely refactoring, so that STD_INSPIRED is more like other macros in this file. --- Makefile | 2 +- localtime.c | 10 +++++----- private.h | 7 +++++-- theory.html | 2 +- 4 files changed, 12 insertions(+), 9 deletions(-) diff --git a/Makefile b/Makefile index 2c09f94..f0cbf7f 100644 --- a/Makefile +++ b/Makefile @@ -363,7 +363,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # -DNETBSD_INSPIRED=0 # to the end of the "CFLAGS=" line. Otherwise, the functions # "localtime_rz", "mktime_z", "tzalloc", and "tzfree" are added to the -# time library, and if STD_INSPIRED is also defined the functions +# time library, and if STD_INSPIRED is also defined to nonzero the functions # "posix2time_z" and "time2posix_z" are added as well. # The functions ending in "_z" (or "_rz") are like their unsuffixed # (or suffixed-by-"_r") counterparts, except with an extra first diff --git a/localtime.c b/localtime.c index 1d22d35..462d054 100644 --- a/localtime.c +++ b/localtime.c @@ -1697,7 +1697,7 @@ gmtime(const time_t *timep) return gmtime_r(timep, &tm); } -#ifdef STD_INSPIRED +#if STD_INSPIRED struct tm * offtime(const time_t *timep, long offset) @@ -1706,7 +1706,7 @@ offtime(const time_t *timep, long offset) return gmtsub(gmtptr, timep, offset, &tm); } -#endif /* defined STD_INSPIRED */ +#endif /* ** Return the number of leap years through the end of the given year @@ -2325,7 +2325,7 @@ mktime(struct tm *tmp) return t; } -#ifdef STD_INSPIRED +#if STD_INSPIRED time_t timelocal(struct tm *tmp) { @@ -2377,7 +2377,7 @@ leapcorr(struct state const *sp, time_t t) ** XXX--is the below the right way to conditionalize?? */ -#ifdef STD_INSPIRED +#if STD_INSPIRED /* NETBSD_INSPIRED_EXTERN functions are exported to callers if NETBSD_INSPIRED is defined, and are private otherwise. */ @@ -2462,7 +2462,7 @@ posix2time(time_t t) return t; } -#endif /* defined STD_INSPIRED */ +#endif /* STD_INSPIRED */ #if TZ_TIME_T diff --git a/private.h b/private.h index 9cb9c24..b5fdf5a 100644 --- a/private.h +++ b/private.h @@ -691,7 +691,10 @@ extern long altzone; ** declarations if time_tz is defined. */ -#ifdef STD_INSPIRED +#ifndef STD_INSPIRED +# define STD_INSPIRED 0 +#endif +#if STD_INSPIRED # if TZ_TIME_T || !defined offtime struct tm *offtime(time_t const *, long); # endif @@ -738,7 +741,7 @@ struct tm *localtime_rz(timezone_t restrict, time_t const *restrict, time_t mktime_z(timezone_t restrict, struct tm *restrict); timezone_t tzalloc(char const *); void tzfree(timezone_t); -# ifdef STD_INSPIRED +# if STD_INSPIRED # if TZ_TIME_T || !defined posix2time_z time_t posix2time_z(timezone_t, time_t) ATTRIBUTE_REPRODUCIBLE; # endif diff --git a/theory.html b/theory.html index 75e347f..f2b798b 100644 --- a/theory.html +++ b/theory.html @@ -1173,7 +1173,7 @@ The vestigial <abbr>API</abbr>s are: </li> <li> The functions that are conditionally compiled - if <code>STD_INSPIRED</code> is defined should, at this point, be + if <code>STD_INSPIRED</code> is nonzero should, at this point, be looked on primarily as food for thought. They are not in any sense "standard compatible" – some are not, in fact, specified in <em>any</em> standard. -- 2.38.1

1 3

New change in Mexico
by Heitor David Pinto Nov. 29, 2022

Nov. 29, 2022

Hello, Mexico is planning to change time zones again. Last month, the whole state of Chihuahua moved to UTC-6 without DST, causing a time change across the border with the US for part of the year. Now the northern municipalities want to have the same time zone as the respective neighboring cities in the US, for example Juárez in UTC-7 with DST, matching El Paso, and Ojinaga in UTC-6 with DST, matching Presidio. The congress of Chihuahua and the federal Chamber and Senate all approved the change, following the combined procedure specified in the new time zone law, and now it awaits the president's approval. The change should occur on the day after the official publication of the law, again on short notice.https://politica.expansion.mx/congreso/2022/11/24/aprueban-que-ayuntamientos-fronterizos-de-chihuahua-tengan-horario-de-verano But there is another problem. The actual law that was passed says that Juárez and Ojinaga will observe UTC-7 and UTC-6 during the DST period, not outside of it. I think that this was an oversight as a result of trying to pass the law through all the chambers very quickly, but I can't believe that no one noticed it. There is a legislative procedure in Mexico called "fe de erratas" to correct obvious mistakes without having to pass the law again, but in this case the correction would have to alter multiple sections so I'm not sure if it will be possible. Either way, I expect confusion in the next days.http://gaceta.diputados.gob.mx/PDF/65/2022/nov/20221124-VII.pdf Regards,Dave

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Re: [tz] [PROPOSED 2/5] Pacify gcc -std=c89 -pedantic with new attributes
by Brian Inglis Nov. 29, 2022

Nov. 29, 2022

On 2022-11-28 12:47, Paul Eggert via tz wrote: > On 2022-11-28 05:40, Philip Newton wrote: >> "have has" is a bit ugly.... > > Yes, I originally used the name "HAVE___HAS_C_ATTRIBUTE", since it tests whether > __has_c_attribute exists and that's the naming convention, but I changed it to > HAVE_HAS_C_ATTRIBUTE as I worried that the three adjacent underscores would be > confusing. If people prefer HAVE___HAS_C_ATTRIBUTE we can easily change to that. > The longer name would be more consistent. "4.2.8 __has_c_attribute The special operator __has_c_attribute (operand) may be used in ‘#if’ and ‘#elif’ expressions in C code to test whether the attribute referenced by its operand is recognized by GCC in attributes using the ‘[[]]’ syntax." How about HAVE_C23_ATTRIBUTE_CHECK, HAVE_C2X_ATTRIBUTE_CHECK, or something similarly more meaningful and less confusing? -- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada La perfection est atteinte Perfection is achieved non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut -- Antoine de Saint-Exupéry

2 1

[tz-announce] 2022g release of tz code and data available
by Paul Eggert via tz-announce Nov. 29, 2022

Nov. 29, 2022

The 2022g release of the tz code and data is available. This release contains the following changes: Briefly: The northern edge of Chihuahua changes to US timekeeping. Much of Greenland stops changing clocks after March 2023. Fix some pre-1996 timestamps in northern Canada. C89 is now deprecated; please use C99 or later. Portability fixes for AIX, libintl, MS-Windows, musl, z/OS In C code, use more C23 features if available. C23 timegm now supported by default Fixes for unlikely integer overflows Changes to future timestamps In the Mexican state of Chihuahua, the border strip near the US will change to agree with nearby US locations on 2022-11-30. The strip's western part, represented by Ciudad Juárez, switches from -06 all year to -07/-06 with US DST rules, like El Paso, TX. The eastern part, represented by Ojinaga, will observe US DST next year, like Presidio, TX. (Thanks to Heitor David Pinto.) A new Zone America/Ciudad_Juarez splits from America/Ojinaga. Much of Greenland, represented by America/Nuuk, stops observing winter time after March 2023, so its daylight saving time becomes standard time. (Thanks to Jonas Nyrup and Jürgen Appel.) Changes to past timestamps Changes for pre-1996 northern Canada (thanks to Chris Walton): Merge America/Iqaluit and America/Pangnirtung into the former, with a backward compatibility link for the latter name. There is no good evidence the two locations differ since 1970. This change affects pre-1996 America/Pangnirtung timestamps. Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and Yellowknife did not observe DST in 1965, and did observe DST from 1972 through 1979. Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28. Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00. (Thanks to Alois Treindl.) Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time), not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.) Changes to code Although tzcode still works with C89, bugs found in recent routine maintenance indicate that bitrot has set in and that in practice C89 is no longer used to build tzcode. As it is a maintenance burden, support for C89 is planned to be removed soon. Instead, please use compilers compatible with C99, C11, C17, or C23. timegm, which tzcode implemented in 1989, will finally be standardized 34 years later as part of C23, so timegm is now supported even if STD_INSPIRED is not defined. Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone. (Problem reported by Đoàn Trần Công Danh.) Fix bug in zic on hosts where malloc(0) yields NULL on success. (Problem reported by Tim McBrayer for AIX 6.1.) Fix zic configuration to avoid linkage failures on some platforms. (Problems reported by Gilmore Davidson and Igor Ivanov.) Work around MS-Windows nmake incompatibility with POSIX. (Problem reported by Manuela Friedrich.) Port mktime and strftime to debugging platforms where accessing uninitialized data has undefined behavior (strftime problem reported by Robert Elz). Check more carefully for unlikely integer overflows, preferring C23 <stdckdint.h> to overflow checking by hand, as the latter has had obscure bugs. Changes to build procedure New Makefile rule check_mild that skips checking whether Link lines are in the file 'backward'. (Inspired by a suggestion from Stephen Colebourne.) Here are links to the release files: https://www.iana.org/time-zones/repository/releases/tzcode2022g.tar.gz https://www.iana.org/time-zones/repository/releases/tzdata2022g.tar.gz https://www.iana.org/time-zones/repository/releases/tzdb-2022g.tar.lz The following convenience links are also available, although they may point to the previous release until the relevant caches are refreshed: https://www.iana.org/time-zones/repository/tzcode-latest.tar.gz https://www.iana.org/time-zones/repository/tzdata-latest.tar.gz https://www.iana.org/time-zones/repository/tzdb-latest.tar.lz Links are also available via plain HTTP, and via FTP from ftp://ftp.iana.org/tz/releases with the same basenames as above. Each release file has a GPG signature, which can be retrieved by appending ".asc" to the above URLs. Copies of these signatures are appended to this message. This release corresponds to commit 4e604e41115182c3ab1185bab4c888822511348e dated 2022-11-29 08:58:31 -0800 and tagged '2022g' in the development GitHub repository at <https://github.com/eggert/tz>. Here are the SHA-512 checksums for the release files: 5188edd8d05238a88da734cf78fadfb57640d4db3e7a0a9dddd70e3071e16b6eebc2e2ab17109b7dafafae68abfbc857df481cfdc3ffe63f7eb1569ea0b5997a tzcode2022g.tar.gz 7f79394295e00e3a24ebdbf9af3bc454a65f432a93b517e7e96c7f9db9949f6f5fdae9892a9d3789ff44ae0eb1bfe4744d36976b4624659af951d26414f94e65 tzdata2022g.tar.gz f471046189f519de5735ac2d8c3edb27cbe925247b06f44634e700e5e4453ec5f715d85256fc74d300bcdaa070a7600fcc054327f2dfe743ab3c0fe404ff83c1 tzdb-2022g.tar.lz Here are the GPG digital signatures for the release files: -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmOGOvAACgkQ7ZfpDmKq fjSI4w/+PkVPCILI34+QeXIm6LLPhEPLxtb7q3rvfoBXk/qyottcPJvQXSAsqX/c Hus6lCNK0COyICVn48rf3ss+GNxLev/ZTMVLUBkH8WrgSe+5lPDjmaZjkbzIGPs8 L9TqE60K8DyeLNnZPf4Pkpx6o5r7uO3iQSN5qFyj5H82mDJ4vcQLZSNvDIA4+sRm +qmsBcn6Gk3EU3u3/YrxhuEY0ymUrJvm5LSG62CqLwA1Pd+REF70Ir5LdO4yJoUS blWe/CLUcnRfzMEK9/NGa1z3GtkisPYBCPnYJ93m2n4ASvFQ+R3t7NCEY2W+96ce 3kSPIX5W2g0/gcDTi1bxdLnQkO4RxtSQnlCjCae58dQNUgOa2X8mdRniRjjYC059 JY35VUzmX9wCPpcuq0iMbpOEWXeWga0ZDRmlZtZCwPKxkw+AhoJQVp5jxGNa4kwZ CZDjQga3ObvN8aQqMi9TpabJ4m2ZdN1yHQ7OTN80N67tHYMAbW0aY3J0JRIVjTHo P+8Y6FaCLzJA73BgnR7faiILXIPtXE54X+koo8x2Uwtrl8/wHsaPTippq96ts6Y6 3Zdr3EAQgAPhYtUgtHoIbLFBLjmyL5sUXOTwG/gMkUYXVkDpeBnc+BHrkv0Sjaw7 Vzz5HthhnSblP9bLB3KPTbbM0t+aypsSOYOSZWnIK8ANI9BdrNQ= =tSyt -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmOGOvAACgkQ7ZfpDmKq fjSedhAAu8XkzqB8NmXDYfEurBCUPe7zCBxBe7yqdt5W+tDA9snOtab3d8Oq7Lsb vNZfh4qHIxNbEYpoXOc0Qce3XKXGgyKDmZeFYQJ0ziqoZXetNLQEmg7T/H2m3GHl eo7K3w2hvyBB26FuDtimE5pzuJo9qJLXDp2SbOAbKa1w5HibyvZBOfcQozZ4CBmE mBc8LzyFY3zOhiy7CGYskqOzatNa0Eid95RkK2RXXTnN965N1qdyOz3z9SkJFH9h MR84VGYBmk0UGdPGmp1imkGmIrO/8AFny19ECCe4F74o2DFSPzANOaEh+i3fIP3d GNR96la9GGopmna+VNQt6zxdw4DHRoNkAupnJ2NVM0lbAMOG0mmwCFkCzW4gzTVm 7NdAtZyH+HjiKYPdQNIHbsvl0K1qIo1yXrb4jTd8eXaxA65msCOOwjqWk7a8ZjrJ NrLNmGeLow9svofEAeLpc9BUgwF90JGIlb+tPYovyj/xSU9vhQl1ZEmFYYdaN781 rGZ5jKtwBZWoAxW1Copf8S3jcxleSVMFo6MTEU+K+svZLd8SH5BnETa0fYWSTzKA uh2Y4V6pFe0/JVVC15mYkytbP6TC6prRmi44jRHtVRDtizGd7FFxYacIApkhBVi2 Qb8Qy+oZySwL+dbRlu+bA9nHIdACtxRouVEWpAecCBLaK3kBb7I= =6g+2 -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmOGOvIACgkQ7ZfpDmKq fjT6/A/5AQdjRCEQngohVPQcxWE57FhHN+3Yq72iCbi64MhnL8sR+fHcni8CRb4f SIxi/tXeLdKJVV8+w7TBeQIDBDHrWXla2NSTHNcGREdp/wMoWagxBzAx3g2qQ7eT Qz6JhG4pHlOGK3u0/RESuCnhS/XmKTYj6BeDNc33LQ4iB0Lh+o9O/rz6jQyO3Y3L 84QMNJ4Edq/pOz9d9T1/cWO1j8Cn4Mled9WdCyOqZnhzRcJdbi/gDydC5aJIj1Fx 5OUrRwblIRVxMbK+kZA4D0lHR56KZb7NsaFGfsnW0m5zHUpXoGNYaFelKlWoRblO OEneM34IgNxsLhe9J9r/epSWB/14PmaY0zdXlNmKqELa7zYiJkiAwucPWtpxkPJG q6WPt4Pk4bWcud9esdgG7vjBz3ffrz2hUrmSMxuwLPHLuPRLrBoeMAmecFixGpea BUmR+XCPV9m19zcnvshBFGuLTNwFZSWBlUB9lWIocXc9cIMo4W/gNdUhnjb9L0+z VtAJzws1VcRV5zpkanwt+K50xjUlunxcRgLbLY2oMCpeDQyxH6DTnUr8RdJeMmvM ZPJYekxG0W8/eEjDOUFIQqvOtK1sQVhCZhjeciDW7to/K1p7DJy+g5g7lJn5KK4B Oz8vqmhdvdoIAK5uezPILpyJT7UpdUhmZ1WwQRqhk6G3jXPigQc= =Kyhr -----END PGP SIGNATURE-----

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America/Nuuk changes from UTC-2 to UTC-2
by Jonas Nyrup Nov. 29, 2022

Nov. 29, 2022

On last Saturday in October 2023 when DST ends America/Nuuk will switch from -03/-02 to -02/-01 https://sermitsiaq.ag/forslagtidsforskel-danmark-mindskes-sommertid-beholdes describes the proposed bill about switching from UTC-3 to UTC-2 and that is not about abolishing DST as they do not want to make a decision on that matter before the rest of EU. https://sermitsiaq.ag/groenland-skifte-tidszone-trods-bekymringer writes that on November 24th 2022 the Parliament of Greenland approved the bill and that *the bill* will take effect on March 25th 2023 at 22:00 when DST begins. Both articles translates well with Google Translate. Inatsisartut = the Parliament of Greenland Naalakkersuisut = the government of Greenland I assume the official document will be published on https://naalakkersuisut.gl/kundgoerelser/2022?sc_lang=da Best regards Jonas Nyrup

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[PROPOSED 0/5] Finish off support for C23 standard attributes
by Paul Eggert Nov. 28, 2022

Nov. 28, 2022

The attached patches update tzcode to use the remaining C23 standard attributes that look useful for tzcode. I don't see any tzcode use for the C23 attributes 'deprecated' and 'nodiscard'. Paul Eggert (5): Use C23 [[noreturn]] if available Pacify gcc -std=c89 -pedantic with new attributes Use C23 [[reproducible]] if available. Use C23 [[unsequenced]] if available Use C23 [[fallthrough]] if available Makefile | 2 +- date.c | 2 +- localtime.c | 4 +-- private.h | 77 ++++++++++++++++++++++++++++++++++++++++++++--------- zdump.c | 10 +++---- zic.c | 32 +++++++++++----------- 6 files changed, 90 insertions(+), 37 deletions(-) -- 2.37.2

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