December 2024 - tz - lists.iana.org

Chile's Aysén Region polled about switching from -04/-03 to -03 all year
by Paul Eggert March 20, 2025

March 20, 2025

Beginning this week and continuing through the end of the month, the citizens of Chile's Aysén Region are being polled virtually for a non-binding resolution[1] to switch from the their current timekeeping regime TZ="America/Santiago" (-04 in winter, -03 in summer) to permanent -03 (like TZ="America/Punta_Arenas"). If this happens, we'll need to create a new Zone America/Coyhaique to record the change, which would likely have practical effect on 2025-04-05 at the earliest. Unfortunately, the SurveyMonkey form used for the poll requires no authentication, which raised plausible worries this week about ballot-stuffing[2]. [1]: https://www.diarioregionalaysen.cl/noticia/actualidad/2024/11/lanzan-consul… [2]: https://www.diarioregionalaysen.cl/noticia/actualidad/2024/11/encuesta-sobr…

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localized date without time
by Alejandro Colomar Feb. 12, 2025

Feb. 12, 2025

Hi Paul, Link: <https://github.com/shadow-maint/shadow/issues/1057> Currently, shadow utils' passwd(1) (and several other programs) uses UTC time when printing. That is: $ passwd -S alx alx P 2023-09-20 0 99999 7 -1 the date from above is a UTC representation of $ sudo cat /etc/shadow | grep alx | cut -f3 -d: 19620 However, shadow utils programs, such as chage(1), use local time in input. That timestamp was set by chage(1), interpreting a local date: $ sudo chage -d 2023-09-21 alx $ sudo cat /etc/shadow | grep alx | cut -f3 -d: 19620 $ date Wed Jul 31 07:54:17 CEST 2024 This is rather confusing, and we think that passwd(1) should also print the date in local time, when printing human-readable dates. However, I think it might be better to show the timezone information together with the date, to be clear that what we're printing is local time. Do you think that's reasonable? Or maybe it's understood that when printing a date some timezone information is implicitly local? I didn't find any way to print timezone information in ISO 8601, if you don't print the time together with the date. That is, ISO 8601 says: C.1.3.1 Date A date string represents one of the following: • year, month, and day (e.g. 2001-02-03) • year and month (e.g. 2008-12 ) • year (e.g. 2008) and C.1.3.2 Date and Time A date/time string is composed according to one of three representations as illustrated in the following three examples: • 2001-02-03T09:30:01 • 2004-01-01T10:10:10Z • 2004-01-01T10:10:10+05:00 but I don't see any way to print something like 2023-09-21+02:00 in standardese. Is this a defect in ISO 8691? I see that in C.1.3.2, it says "Zone-offset may be omitted or included", so I guess we can just omit it. What do you think we should do? Thanks! And have a lovely day! Alex -- <https://www.alejandro-colomar.es/>

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Paraguay may adopt permanent DST soon
by Heitor David Pinto Jan. 13, 2025

Jan. 13, 2025

Today the Congress of Paraguay passed a bill to observe UTC-3 permanently, equivalent to permanent DST. The bill still needs to be approved by the president. https://www.abc.com.py/politica/2024/09/24/congreso-sanciona-horario-de-ver… The text of the bill says that it would enter into force on the first Sunday in October 2024, the same date currently scheduled to start DST. But in practice, it would only make a difference from the fourth Sunday of March 2025, the date currently scheduled to end DST. https://silpy.congreso.gov.py/web/expediente/132531

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Y2K on the radio
by Arthur Olson Dec. 31, 2024

Dec. 31, 2024

With a New Year looming, an NPR Y2K review. (Alas, no mention of T2G in 2038.) @dashdashado https://www.npr.org/2024/12/28/nx-s1-5116271/y2k-year-2000-preparations

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[PROPOSED] For timestamps compare to HEAD not to index
by Paul Eggert Dec. 30, 2024

Dec. 30, 2024

Problem reported by Bruno Haible in: https://lists.gnu.org/r/bug-gnulib/2024-12/msg00245.html * Makefile (set-timestamps.out): When comparing working file to repository, Use ‘git diff HEAD’ instead of plain ‘git diff’. --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index ffdbfe3b..e00b0f32 100644 --- a/Makefile +++ b/Makefile @@ -1104,7 +1104,7 @@ set-timestamps.out: $(EIGHT_YARDS) touch -md @1 test.out; then \ rm -f test.out && \ for file in $$files; do \ - if git diff --quiet $$file; then \ + if git diff --quiet HEAD $$file; then \ time=$$(TZ=UTC0 git log -1 \ --format='tformat:%cd' \ --date='format:%Y-%m-%dT%H:%M:%SZ' \ -- 2.47.1

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Deprecate two digit year formats %D %g %y
by Brian Inglis Dec. 29, 2024

Dec. 29, 2024

Hi folks, [Spurred by NPR Y2K review article.] Could we please all make a New Year's resolution to stop people from reviving two digit year formats that are starting to reappear, making it impossible to figure out some intended dates, and officially deprecate all two digit year formats %D %g %y across all standards, and tools default to options like gcc's and clang's -Wformat-y2k (included in -Wformat=2) and clang's -Wdeprecate. -- 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

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Request for inclusion of Trivandrum in the IANA Time Zone Database
by Anish shivaraj Dec. 28, 2024

Dec. 28, 2024

Dear tzdata Maintainers, I am writing to propose the inclusion of Trivandrum (Thiruvananthapuram) as a new entry in the IANA Time Zone Database (tzdata). As the capital city of Kerala, Trivandrum holds significant historical, economic, and technological importance, and its addition to the database would reflect its growing prominence. Justification for Inclusion Population and Prominence With a population exceeding 1 million, Trivandrum is well above the 300,000 threshold for inclusion.The city serves as a political, cultural, and economic hub in southern India. Economic Growth and Commercial Significance Vizhinjam International Seaport: Trivandrum is home to India’s first transshipment port, the Vizhinjam International Seaport, which is expected to position the city as a major player in global shipping and logistics. Emerging Commercial Hub: The growth of the Vizhinjam port has already made Trivandrum an important center for commerce, attractingsignificant investments and fostering local economic development. Technological and Space Research Importance India’s First IT Park: Technopark in Trivandrum is the country’s first and one of the largest IT parks, contributing greatly to India’s IT industry. Space Research and Education: The city houses the Vikram Sarabhai Space Centre (VSSC), a key institution for India’s space exploration efforts. Trivandrum also hosts the Indian Institute of Space Science and Technology (IIST) and the Kerala Space Park, making it a critical hub for space research and innovation. Eligibility Based on Time Zone Criteria Unique Timekeeping History: Trivandrum once had its own local mean time before the adoption of Indian Standard Time (IST), making this distinction relevant for its case. Representative Need: As an emerging commercial, technological,and research center, a separate time zone entry would provide better representation for the region’s users and applications. Alignment with tzdata Objectives - Trivandrum meets the criteria of significant population, historical relevance, and global contributions to shipping, IT, and space research, making it a suitable candidate for inclusion. Proposed Time Zone Entry We suggest adding the following entry: Zone Asia/Trivandrum +05:30 - Trivandrum Standard Time Including Trivandrum in the tzdata database would provide better localization and reflect its growing importance. Thank you for considering this request. Should you require further information or clarification, please do not hesitate to reach out. Best regards, Anish Sivarajan

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Re: Iana build failures on Windows
by Paul Eggert Dec. 19, 2024

Dec. 19, 2024

On 2024-12-17 07:53, Manuela Friedrich wrote: > It's worth noticing that I had to add -DHAVE_SYS_STAT_H=0 to the tools.ini > file we use on Windows. Thanks for mentioning that, but unfortunately I don't know why -DHAVE_SYS_STAT_H=0 was needed (I don't use MS-Windows). Some fumbling with Microsoft documentation eventually led me to <https://learn.microsoft.com/en-us/cpp/c-runtime-library/compatibility?view=…> which hints (but does not say) that by default MS-Windows <sys/stat.h> doesn't define the 'stat' function if you use some compilation options. I installed the attached patch to try to work around this portability problem. Does this patch fix things so that -DHAVE_SYS_STAT_H=0 need not be added to tools.ini? If not, what problems do you observe? With the patch, do you see warnings when compiling? Does compiling with -D_CRT_SECURE_NO_WARNINGS cut down on the number of warnings? What's in your tools.ini file for building tzcode?

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Re: Iana build failures on Windows
by Paul Eggert Dec. 17, 2024

Dec. 17, 2024

On 2024-12-15 23:11, Manuela Friedrich wrote: > localtime.c > d:\devsrc\treasure_test\iana\tmp\private.h(872): warning C4005: 'max': > macro redefinition > C:\Program Files (x86)\Windows > Kits\10\include\10.0.16299.0\ucrt\stdlib.h(1300): note: see previous > definition of 'max' > d:\devsrc\treasure_test\iana\tmp\private.h(873): warning C4005: 'min': > macro redefinition > C:\Program Files (x86)\Windows > Kits\10\include\10.0.16299.0\ucrt\stdlib.h(1301): note: see previous > definition of 'min' > localtime.c(418): error C2065: 'utc': undeclared identifier > localtime.c(418): warning C4047: ':': 'const char *' differs in levels of > indirection from 'int' > localtime.c(1449): error C2065: 'utc': undeclared identifier > localtime.c(1449): warning C4047: 'function': 'const char *' differs in > levels of indirection from 'int' > localtime.c(1449): warning C4024: 'strcpy': different types for formal and > actual parameter 2 > NMAKE : U1077: '"C:\Program Files (x86)\Microsoft Visual > Studio\2017\Professional\VC\Tools\MSVC\14.12.25827\bin\HostX64\x64\cl.EXE"' > : return code '0x2' Thanks for reporting these build glitches on MS-Windows. I installed the attached patches; please give them a try, as I don't use that platform.

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Daylight Saving in the news
by Arthur Olson Dec. 15, 2024

Dec. 15, 2024

"Trump vows to end 'very costly' daylight saving time" (While Mexico may not pay for it, Mexico and Canada may follow suit.) https://www.bbc.com/news/articles/cn9gjvgv4neo @dashdashado

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How permanent daylight saving time or permanent standard time would affect the USA
by Jonathan Leffler Dec. 13, 2024

Dec. 13, 2024

Article in the Washington Post about how early or late you would be in the dark if the USA adopted permanent daylight saving time or permanent standard time (compared with now). https://www.washingtonpost.com/nation/interactive/2024/no-daylight-saving-t… With decent interactive graphics. I'm a subscriber; I don't know if there's a paywall in place. -- Jonathan Leffler <jonathan.leffler(a)gmail.com> #include <disclaimer.h> Guardian of DBD::Informix - v2018.1031 - http://dbi.perl.org "Blessed are we who can laugh at ourselves, for we shall never cease to be amused."

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[PROPOSED] Fix asctime.o, strftime.o dependencies
by Paul Eggert Dec. 11, 2024

Dec. 11, 2024

* Makefile (asctime.o): Don’t depend on tzfile.h. (strftime.o): Depend on tzdir.h, as it’s included indirectly via localtime.c if MKTIME_MIGHT_OVERFLOW. --- Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index 2aafdc24..8faab6ff 100644 --- a/Makefile +++ b/Makefile @@ -1355,11 +1355,11 @@ long-long.ck unsigned.ck: $(VERSION_DEPS) zonenames: tzdata.zi @$(AWK) '/^Z/ { print $$2 } /^L/ { print $$3 }' tzdata.zi -asctime.o: private.h tzfile.h +asctime.o: private.h date.o: private.h difftime.o: private.h -localtime.o: private.h tzfile.h tzdir.h -strftime.o: localtime.c private.h tzfile.h +localtime.o: private.h tzdir.h tzfile.h +strftime.o: localtime.c private.h tzdir.h tzfile.h zdump.o: version.h zic.o: private.h tzfile.h tzdir.h version.h -- 2.47.1

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[PROPOSED] Fix to2050.tzs timestamp in distributed tarball
by Paul Eggert Dec. 11, 2024

Dec. 11, 2024

* Makefile (TZS_DEPS): Remove asctime.c and add localtime.c. --- Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 5473dedd..2aafdc24 100644 --- a/Makefile +++ b/Makefile @@ -615,8 +615,8 @@ TZS_YEAR= 2050 TZS_CUTOFF_FLAG= -c $(TZS_YEAR) TZS= to$(TZS_YEAR).tzs TZS_NEW= to$(TZS_YEAR)new.tzs -TZS_DEPS= $(YDATA) asctime.c localtime.c \ - private.h tzfile.h zdump.c zic.c +TZS_DEPS= $(YDATA) localtime.c private.h \ + strftime.c tzfile.h zdump.c zic.c TZDATA_DIST = $(COMMON) $(DATA) $(MISC) # EIGHT_YARDS is just a yard short of the whole ENCHILADA. EIGHT_YARDS = $(TZDATA_DIST) $(DOCS) $(SOURCES) tzdata.zi -- 2.47.1

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Add ICU's Etc/Unknown Zone to IANA Time Zone Database?
by Justin Grant Dec. 11, 2024

Dec. 11, 2024

Hi TZ friends - Should the time zone identifier "Etc/Unknown" (standardized in Unicode Technical Standard 35 and used by the ICU <https://icu.unicode.org/> library that implements time zone support in all major web browsers, in Java, and in other platforms) be added to the IANA Time Zone Database? Etc/Unknown would behave the same as the existing time zone identifier "Factory". Ideally, Etc/Unknown could be a Zone and Factory could be turned into a Link pointing to Etc/Unknown, because both of them have the meaning of "the time zone of this computer is not known" but Etc/Unknown is more self-describing and is better aligned with modern Zone naming conventions. Here's more context: "Etc/Unknown" is standardized in https://unicode.org/reports/tr35/#Time_Zone_Identifiers. Here's the relevant text from the standard: > There is a special code "unk" for an Unknown or Invalid time zone. > This can be expressed in the tz database style ID "Etc/Unknown", > although it is not defined in the tz database. Following this standard, Etc/Unknown is returned by ICU <https://icu.unicode.org/> when the time zone of a computer cannot be determined. Here's an example of an ICU method that can return Etc/Unknown: icu::TimeZone::detectHostTimeZone() <https://unicode-org.github.io/icu-docs/apidoc/dev/icu4c/classicu_1_1TimeZon…> . The fact that Etc/Unknown looks like an IANA identifier but is not actually in TZDB has been a long-running source of problems. Most recently, this week Chrome is rushing out a patch <https://issues.chromium.org/issues/381620359> that reverted a recent change that added support for the "Factory" zone by making it an alias for "Etc/Unknown". GIven that ICU previously didn't recognize Factory and so returned Etc/Unknown for computers in the Factory zone, this was assumed by everyone to be a safe change. But this change turned out to break some 3rd-party libraries and had to be reverted. After discussing this recent bug with engineers at Google, our consensus was that it'd be helpful for the time zone ecosystem if Etc/Unknown stopped being a special case and started being a regular Zone in the IANA Time Zone database. Especially if we could Link-ify Factory at the same time so that Zone picker UIs won't have two distinct "I don't know what time zone this is" choices. Thanks for considering this proposal. Best, Justin Grant

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[PROPOSED] Fix unlikely multithreaded file descriptor leak
by Paul Eggert Dec. 9, 2024

Dec. 9, 2024

On multithreaded platforms, tzset could leak a file descriptor into a forked or execed process. Fix the leak. While we’re at it, don’t let the TZif file become the controlling tty. * NEWS: Mention this. * localtime.c (O_CLOEXEC, O_CLOFORK, O_IGNORE_CTTY, O_NOCTTY): Default to 0. (tzloadbody): Use these flags when opening the TZif file. --- NEWS | 5 +++++ localtime.c | 22 +++++++++++++++++----- 2 files changed, 22 insertions(+), 5 deletions(-) diff --git a/NEWS b/NEWS index 79686147..2fc7bb19 100644 --- a/NEWS +++ b/NEWS @@ -56,6 +56,11 @@ Unreleased, experimental changes PTRDIFF_MAX, a limit forced by C anyway; formerly tzcode silently misbehaved unless TZNAME_MAXIMUM was less than INT_MAX. + tzset and related functions no longer leak a file descriptor if + another thread forks or execs at about the same time and if the + platform has O_CLOFORK and O_CLOEXEC respectively. Also, the + functions no longer let a TZif file become a controlling terminal. + Changes to documentation The name Etc/Unknown is now reserved: it will not be used by TZDB. diff --git a/localtime.c b/localtime.c index 492965d9..f92676c6 100644 --- a/localtime.c +++ b/localtime.c @@ -96,12 +96,23 @@ typedef intmax_t timex_t; # define TZ_ABBR_ERR_CHAR '_' #endif /* !defined TZ_ABBR_ERR_CHAR */ -/* -** Support non-POSIX platforms that distinguish between text and binary files. -*/ +/* Port to platforms that lack some O_* flags. Unless otherwise + specified, the flags are standardized by POSIX. */ #ifndef O_BINARY -# define O_BINARY 0 +# define O_BINARY 0 /* MS-Windows */ +#endif +#ifndef O_CLOEXEC +# define O_CLOEXEC 0 +#endif +#ifndef O_CLOFORK +# define O_CLOFORK 0 +#endif +#ifndef O_IGNORE_CTTY +# define O_IGNORE_CTTY 0 /* GNU/Hurd */ +#endif +#ifndef O_NOCTTY +# define O_NOCTTY 0 #endif #ifndef WILDABBR @@ -542,7 +553,8 @@ tzloadbody(char const *name, struct state *sp, bool doextend, } if (doaccess && access(name, R_OK) != 0) return errno; - fid = open(name, O_RDONLY | O_BINARY); + fid = open(name, (O_RDONLY | O_BINARY | O_CLOEXEC | O_CLOFORK + | O_IGNORE_CTTY | O_NOCTTY)); if (fid < 0) return errno; -- 2.47.0

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US Department of Transportation map of US timezones
by Roozbeh Pournader Dec. 7, 2024

Dec. 7, 2024

I just found out through https://x.com/RedistrictNet/status/1863742503242875046 That the US Department of Transportation has just rolled out an official map of US timezones. It's supposed to be at: https://geodata.bts.gov/datasets/usdot::time-zones/about (It doesn't load for me at the moment, possibly due to high demand.) Roozbeh

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[PROPOSED] Fix checknow confusing diagnostics
by Paul Eggert Dec. 7, 2024

Dec. 7, 2024

* checknow.awk: Do not report a duplicate (and confusing) diagnostic when a zone has no data. --- checknow.awk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/checknow.awk b/checknow.awk index 8b7881d2..450490ee 100644 --- a/checknow.awk +++ b/checknow.awk @@ -44,7 +44,7 @@ BEGIN { END { for (zone in zone_data) { data = zone_data[zone] - if (!zonenow[data]) { + if (data && !zonenow[data]) { printf "Zone table should have one of:%s\n", zones[data] zonenow[data] = zone # This suppresses duplicate diagnostics. status = 1 -- 2.47.0

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[PROPOSED 1/3] Pacify gcc -Wsuggest-attribute=format sans snprintf in zdump
by Paul Eggert Dec. 1, 2024

Dec. 1, 2024

* zdump.c (my_snprintf): Now a static function defined only if !HAVE_SNPRINTF, with "#define snprintf my_sprintf" at the end. This lessens disruption to mainline code. All uses changed. Add ATTRIBUTE_FORMAT((printf, 3, 4)) to pacify gcc -Wsuggest-attribute=format. --- zdump.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/zdump.c b/zdump.c index c988f6b3..ea051adf 100644 --- a/zdump.c +++ b/zdump.c @@ -914,13 +914,10 @@ showextrema(timezone_t tz, char *zone, time_t lo, struct tm *lotmp, time_t hi) } } -#if HAVE_SNPRINTF -# define my_snprintf snprintf -#else +/* On pre-C99 platforms, a snprintf substitute good enough for us. */ +#if !HAVE_SNPRINTF # include <stdarg.h> - -/* A substitute for snprintf that is good enough for zdump. */ -static int +ATTRIBUTE_FORMAT((printf, 3, 4)) static int my_snprintf(char *s, size_t size, char const *format, ...) { int n; @@ -948,6 +945,7 @@ my_snprintf(char *s, size_t size, char const *format, ...) va_end(args); return n; } +# define snprintf my_snprintf #endif /* Store into BUF, of size SIZE, a formatted local time taken from *TM. @@ -962,10 +960,10 @@ format_local_time(char *buf, ptrdiff_t size, struct tm const *tm) { int ss = tm->tm_sec, mm = tm->tm_min, hh = tm->tm_hour; return (ss - ? my_snprintf(buf, size, "%02d:%02d:%02d", hh, mm, ss) + ? snprintf(buf, size, "%02d:%02d:%02d", hh, mm, ss) : mm - ? my_snprintf(buf, size, "%02d:%02d", hh, mm) - : my_snprintf(buf, size, "%02d", hh)); + ? snprintf(buf, size, "%02d:%02d", hh, mm) + : snprintf(buf, size, "%02d", hh)); } /* Store into BUF, of size SIZE, a formatted UT offset for the @@ -1000,10 +998,10 @@ format_utc_offset(char *buf, ptrdiff_t size, struct tm const *tm, time_t t) mm = off / 60 % 60; hh = off / 60 / 60; return (ss || 100 <= hh - ? my_snprintf(buf, size, "%c%02ld%02d%02d", sign, hh, mm, ss) + ? snprintf(buf, size, "%c%02ld%02d%02d", sign, hh, mm, ss) : mm - ? my_snprintf(buf, size, "%c%02ld%02d", sign, hh, mm) - : my_snprintf(buf, size, "%c%02ld", sign, hh)); + ? snprintf(buf, size, "%c%02ld%02d", sign, hh, mm) + : snprintf(buf, size, "%c%02ld", sign, hh)); } /* Store into BUF (of size SIZE) a quoted string representation of P. @@ -1106,7 +1104,7 @@ istrftime(char *buf, ptrdiff_t size, char const *time_fmt, for (abp = ab; is_alpha(*abp); abp++) continue; len = (!*abp && *ab - ? my_snprintf(b, s, "%s", ab) + ? snprintf(b, s, "%s", ab) : format_quoted_string(b, s, ab)); if (s <= len) return false; @@ -1114,7 +1112,7 @@ istrftime(char *buf, ptrdiff_t size, char const *time_fmt, } formatted_len = (tm->tm_isdst - ? my_snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst) + ? snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst) : 0); } break; -- 2.43.0

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