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More than 2 transitions per year for Asia/Gaza & Hebron in 2068+
by Dave Rolsky Dec. 30, 2023

Dec. 30, 2023

Hi all, With the latest release (2023d) I'm seeing some surprising output from zdump for the Asia/Gaza & Asia/Hebron zones: $> zdump -v Asia/Hebron ... Asia/Hebron Fri Mar 23 23:59:59 2068 UT = Sat Mar 24 01:59:59 2068 EET isdst=0 gmtoff=7200 Asia/Hebron Sat Mar 24 00:00:00 2068 UT = Sat Mar 24 03:00:00 2068 EEST isdst=1 gmtoff=10800 Asia/Hebron Fri Oct 19 22:59:59 2068 UT = Sat Oct 20 01:59:59 2068 EEST isdst=1 gmtoff=10800 Asia/Hebron Fri Oct 19 23:00:00 2068 UT = Sat Oct 20 01:00:00 2068 EET isdst=0 gmtoff=7200 Asia/Hebron Fri Mar 29 23:59:59 2069 UT = Sat Mar 30 01:59:59 2069 EET isdst=0 gmtoff=7200 Asia/Hebron Sat Mar 30 00:00:00 2069 UT = Sat Mar 30 03:00:00 2069 EEST isdst=1 gmtoff=10800 Asia/Hebron Fri Oct 11 22:59:59 2069 UT = Sat Oct 12 01:59:59 2069 EEST isdst=1 gmtoff=10800 Asia/Hebron Fri Oct 11 23:00:00 2069 UT = Sat Oct 12 01:00:00 2069 EET isdst=0 gmtoff=7200 This pattern of >2 transitions per year continues from that year. Is this correct? It seems awfully weird. Cheers, Dave Rolsky http://blog.urth.org https://github.com/autarch

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[tz-announce] 2023d release of tz code and data available
by Paul Eggert via tz-announce Dec. 22, 2023

Dec. 22, 2023

The 2023d release of the tz code and data is available. This release contains the following changes: Briefly: Ittoqqortoormiit, Greenland changes time zones on 2024-03-31. Vostok, Antarctica changed time zones on 2023-12-18. Casey, Antarctica changed time zones five times since 2020. Code and data fixes for Palestine timestamps starting in 2072. A new data file zonenow.tab for timestamps starting now. Changes to future timestamps Ittoqqortoormiit, Greenland (America/Scoresbysund) joins most of the rest of Greenland's timekeeping practice on 2024-03-31, by changing its time zone from -01/+00 to -02/-01 at the same moment as the spring-forward transition. Its clocks will therefore not spring forward as previously scheduled. The time zone change reverts to its common practice before 1981. Fix predictions for DST transitions in Palestine in 2072-2075, correcting a typo introduced in 2023a. Changes to past and future timestamps Vostok, Antarctica changed to +05 on 2023-12-18. It had been at +07 (not +06) for years. (Thanks to Zakhary V. Akulov.) Change data for Casey, Antarctica to agree with timeanddate.com, by adding five time zone changes since 2020. Casey is now at +08 instead of +11. Changes to past tm_isdst flags Much of Greenland, represented by America/Nuuk, changed its standard time from -03 to -02 on 2023-03-25, not on 2023-10-28. This does not affect UTC offsets, only the tm_isdst flag. (Thanks to Thomas M. Steenholdt.) New data file A new data file zonenow.tab helps configure applications that use timestamps dated from now on. This simplifies configuration, since users choose from a smaller Zone set. The file's format is experimental and subject to change. Changes to code localtime.c no longer mishandles TZif files that contain a single transition into a DST regime. Previously, it incorrectly assumed DST was in effect before the transition too. (Thanks to Alois Treindl for debugging help.) localtime.c's timeoff no longer collides with OpenBSD 7.4. The C code now uses _Generic only if __STDC_VERSION__ says the compiler is C11 or later. tzselect now optionally reads zonenow.tab, to simplify when configuring only for timestamps dated from now on. tzselect no longer creates temporary files. tzselect no longer mishandles the following: Spaces and most other special characters in BUGEMAIL, PACKAGE, TZDIR, and VERSION. TZ strings when using mawk 1.4.3, which mishandles regular expressions of the form /X{2,}/. ISO 6709 coordinates when using an awk that lacks the GNU extension of newlines in -v option-arguments. Non UTF-8 locales when using an iconv command that lacks the GNU //TRANSLIT extension. zic no longer mishandles data for Palestine after the year 2075. Previously, it incorrectly omitted post-2075 transitions that are predicted for just before and just after Ramadan. (Thanks to Ken Murchison for debugging help.) zic now works again on Linux 2.6.16 and 2.6.17 (2006). (Problem reported by Rune Torgersen.) Changes to build procedure The Makefile is now more compatible with POSIX: * It no longer defines AR, CC, CFLAGS, LDFLAGS, and SHELL. * It no longer uses its own 'cc' in place of CC. * It now uses ARFLAGS, with default specified by POSIX. * It does not use LFLAGS incompatibly with POSIX. * 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 built by 'make', not in a $(CC) -D option. Also, TZDEFAULT is now treated like TZDIR as they have similar roles. Changes to commentary Limitations and hazards of the optional support for obsolescent C89 platforms are documented better, along with a tentative schedule for removing this support. Here are links to the release files: https://www.iana.org/time-zones/repository/releases/tzcode2023d.tar.gz https://www.iana.org/time-zones/repository/releases/tzdata2023d.tar.gz https://www.iana.org/time-zones/repository/releases/tzdb-2023d.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 cc48c2dfa2f3c21d25ab108bba978b0307ecf0e8 dated 2023-12-21 20:02:24 -0800 and tagged '2023d' in the development GitHub repository at <https://github.com/eggert/tz>. Here are the SHA-512 checksums for the release files: 3994a5a060a7a5fffc6585f5191cf7679f9f9be44dbcee4d67d0e42c5b6020c308cb55caf8bf8d51554697665105a174cb470c8c4fc069438350f3bac725709b tzcode2023d.tar.gz 81832b2d738c28cecbcb3906cc07568c5ae574adc9de35b25d4bf613581c92d471d67213b4261a56f0ec02efcf211b4e298b7e1dc367c972e726b0a2e9498df4 tzdata2023d.tar.gz 334f02e20d5841e60ddbdbf074f231c1564c9ac7781bad8c9813e3045d3ea0422acd1caa23a63466ca6113c396d701ccbef29669749ae844d218e4e601a9ee02 tzdb-2023d.tar.lz Here are GPG digital signatures for the release files: -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmWFCxgACgkQ7ZfpDmKq fjQjkhAAuWOz1EC8Wo3ug3fU4ns0KJIk7fTV6yNKUGrjuxOmc15+Dxb8QtLKagTr 9bZBsnI1v3krgMclbuEirbkeacST0rnKbW0Dije20ZZXYUaDQ3J3nGbjOSfcnLNk dYODCQKVarkbZ70+mmm4ytvwpuQDY5W/WcP/8qXB+wTQQukAGHlglDEcdQKIwz1L aMqGzO6hd5Wv/mw0Nz16BIoEqntKLzSJE3h5h92lBhVA0em02jSrTzBZePW9k3qb VG9qjui5nrWW4nJZln15XKBz7omo7e+NEP9UFzvCWTgwKQkdGNMbTjj6cBh8wKMX SPgCBvHyGx2UzukdxXzzCEn471Ug1XNHJAAfvlEd3FkrPcUc5Hj7w0chKYibQTsm LrjUSzbIVX5EBIxEDaGWrDbahLsaw+w+Ui09nFZ/sSB1LcbCa9eGsYGHvicnBu2S RZhZWk7lL8rtQjFjOMeoLy5j3rX8zwE07BNgjmnfkxGkZJ7XdriWy937d5SLvkKN /gaaaJ/32NDzTdzkhdOLcqKi+x2wCODCNDThfM4JiOIzCFkeSlaYnqShW7CcV/9c Nh9VM9zLKkApqL9Mr/kPqT5+FmN6GunMK3y9qNwA8ROq7DpAgUWoc4ZGoeNYy5I9 XbSk2ua/gAFfJsubjZ56//eEgFsLOLcE2eyFpS0WPcIA9qVk+Jc= =ZPDg -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmWFCxkACgkQ7ZfpDmKq fjRuUxAAoioAZhZkP9DnoNvoo2YG+g4gxS4GIIw1KK6nhZqIN8F9e4wrvw6/++x/ 7FNP2+KV7ObTNlqeONv2niAL8zuFq8VhkN60D4j1qEu9H21Wxp6HFWOFEWi8l5TS l6dp4S1Rb5LmCVlbj2MbrbE6Qc+QptSdGuw12MQR34b5F8pX39vt+edMfHvA2lw0 KhMkELOaBhKCAoiVHC8onUZvCg5qEpynQ88LpKgnLWslT9fcU3m0mCuiXldSn5kp KppIlAFp6WuaKIJiuj61gjH9Py00PM7ww1+0eZbnbametmM3E2Or+YoP1pm5bIy8 77+iVCvBu+B1aW/cC1h2k3vLRUg8sFxMvGJdpow6JN1D+2e3Flk8+A8DPwRXtCRV yjjGOzIltbWwD7fisPKbvXSrVlQmMrNLMoyQcljZbYUa5nhTMoCiv+yed/DzG2ZF pwAJguKenamOiRpChFfkrVXBn/AWr4G7FVAogckFClz7qP6KSekJ0h1MzUw31c5g 8XZEwXNO2RGLbhgCw5uLg3V2KUvurSYGSBB46TnMNBLz1xRNelzkJ7XvJVIhxCEN L1t32v4jbD4YtXHqNugVId9uY3x8ed8SPdFy+8C2OqKY0TiWOTiAH2rz3vcz2L6O rsubE+4g/LUQI0fS9hTcabD9RcsP3k3/h2fZYLORM6frwuZA82U= =ylD7 -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmWFCxoACgkQ7ZfpDmKq fjQiug//UW82Sq338kOG4pKEgEjoinNowfqA0cb5yZgg/wI9KKm3MSd2DqVOpySI MUwLzE2mqopxLsqrg+erdAgnaw67UqE7nkWui9zKYaON4D6XkwnFEyJTwefYzEUu WevUIMDreoK20ifcCYRNyvjFU6ik0MUVq1E5EZcli5yip4E7MRNQfiLemEe65shr ivUXndETTY06kLCf8Os7MyPxrrFc1IBB8f8fuRXcIgqqBRO+2YeViIh8iIbWIImF lO4S3Knh8Pd+6fOG5AGUcD8V7h5mZhFOVhTaKy6EWvU/98SZdGRIfszeHmgLCKmq CdKCO1K8XOITkqSWCenfTXnNELm/hsnuGPBcaRBxWXFNVLBaSaufmw0+h5IsviCo DwMqp3z7byOlNwYqeF+bYCXaoJ5ZATjCK82D5xKGLPs394/f6m46XEcQR9AU2JUR N59J0smHiH9lNzEuIcM7S8Rwwm05uVNUdHBubkz4YEWeruT5ZNlhRUnfq63Vv4ol UN5Lwqqew5V5kXmKueBHd5czN65z96EVsJTs9xMuS2OR2uekCmtqaYKhpL5DsFPH xcaAADZ1BvR2BJUmMSyXT/slyEjyK8I20irZaBGfSmAiHp9o2AW3K1pXLAXasa4E K+OAFiIqtuH7zGOIcDcj8A50KD//70nn8DPgk9S1HuQ4uTKcXBg= =IyqX -----END PGP SIGNATURE-----

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Re: [tz] Antarctic research base Vostok local time
by Paul Eggert Dec. 21, 2023

Dec. 21, 2023

Unfortunately, it doesn't suffice to know just the current UTC offset. We would need to know the past UTC offsets back to at least 1970, and also to know when the base was and wasn't inhabited during that period. And we need citations to sources for this information.

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Re: [tz] Definition of "timezone"
by Paul Eggert Dec. 21, 2023

Dec. 21, 2023

On 2023-12-21 07:08, ApoY2k wrote: > do you (or your > peers on the tz project) consider a "timezone" to be inherently tied to the > real-world geographical features they are used for, or is the word > "timezone" in this context more broader understood as "any 'Zone' entry in > the tzdb" - which would e.g. also denote "Etc/UTC" as a "real timezone". I'll cc this to tz(a)iana.org to see what others think. There's no formal definition. In TZDB commentary I tend to use "timezone" roughly as a synonym for "TZ setting", that is, for valid values of the TZ environment variable. In that sense there is a huge number of timezones since this includes POSIX TZ strings, and "Europe/London", "Etc/UTC" and "GMT0BST,M3.5.0/1,M10.5.0" all denote timezones. In contrast, the TZDB commentary uses "time zone" for the more common understanding in the real world, that is, the maximal-sized geographical region where clocks currently all have the same reading. In that sense there are 37 time zones right now, though the number changes depending on when you ask the question. The TZDB commentary doesn't use a name for the concept you're asking about, but I suppose "geographical timezone" would do. Admittedly the terminology is not always clear in this area. PS. I got the number "37" as follows: $ tzselect Please identify a location so that time zone rules can be set correctly. Please select a continent, ocean, "coord", "TZ", "time", or "now". 1) Africa 2) Americas 3) Antarctica 4) Arctic Ocean 5) Asia 6) Atlantic Ocean 7) Australia 8) Europe 9) Indian Ocean 10) Pacific Ocean 11) coord - I want to use geographical coordinates. 12) TZ - I want to specify the timezone using the POSIX TZ format. 13) time - I know local time already. 14) now - Like "time", but configure only for timestamps from now on. #? 14 The system says Universal Time is Thu Dec 21 20:00. Assuming that's correct, what is the local time? 1) Thu Dec 21 09:00 14) Thu Dec 21 20:00 27) Fri Dec 22 04:00 2) Thu Dec 21 10:00 15) Thu Dec 21 21:00 28) Fri Dec 22 04:45 3) Thu Dec 21 10:30 16) Thu Dec 21 22:00 29) Fri Dec 22 05:00 4) Thu Dec 21 11:00 17) Thu Dec 21 23:00 30) Fri Dec 22 05:30 5) Thu Dec 21 12:00 18) Thu Dec 21 23:30 31) Fri Dec 22 06:00 6) Thu Dec 21 13:00 19) Fri Dec 22 00:00 32) Fri Dec 22 06:30 7) Thu Dec 21 14:00 20) Fri Dec 22 00:30 33) Fri Dec 22 07:00 8) Thu Dec 21 15:00 21) Fri Dec 22 01:00 34) Fri Dec 22 08:00 9) Thu Dec 21 16:00 22) Fri Dec 22 01:30 35) Fri Dec 22 09:00 10) Thu Dec 21 16:30 23) Fri Dec 22 01:45 36) Fri Dec 22 09:45 11) Thu Dec 21 17:00 24) Fri Dec 22 02:00 37) Fri Dec 22 10:00 12) Thu Dec 21 18:00 25) Fri Dec 22 02:30 13) Thu Dec 21 19:00 26) Fri Dec 22 03:00 #?

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[PROPOSED] * zonenow.tab: Explain comments column.
by Paul Eggert Dec. 21, 2023

Dec. 21, 2023

--- zonenow.tab | 3 +++ 1 file changed, 3 insertions(+) diff --git a/zonenow.tab b/zonenow.tab index aea2a90e..2dbe8f00 100644 --- a/zonenow.tab +++ b/zonenow.tab @@ -16,6 +16,9 @@ # first by standard time UTC offset; # then, if DST is used, by daylight saving UTC offset; # then by time zone abbreviation. +# 4. Every timezone has a nonempty comments column, with wording +# distinguishing the timezone only from other timezones with the +# same UTC offset at some point during the year. # # The format of this table is experimental, and may change in future versions. # -- 2.43.0

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Re: [tz] [PROPOSED 00/18] tzselect improvements for configuring "from now on"
by Paul Eggert Dec. 21, 2023

Dec. 21, 2023

On 2023-12-21 03:46, Dimitry Andric wrote: > The problem is that c99 effectively runs "cc -std=iso9899:1999 -pedantic". _Generic is a C11 extension so it will then warn about that. Thanks for doing the testing. I ran into that bug with _Generic on FreeBSD 14 and installed the following workaround, which fixed things for me: https://mm.icann.org/pipermail/tz/2023-December/033364.html so if you do a "git pull" I hope this problem is fixed on FreeBSD 15-CURRENT as well. I view this as merely a bug in how clang does things. When you run 'make' in POSIX mode (by putting a ".POSIX:" line at the start of the Makefile), 'make' defaults CC to c99 (as current POSIX requires). In tzcode, even before the abovementioned patch, all uses of _Generic were protected by "#if __has_extension(c_generic_selections)" but clang complain about the uses anyway. The patch works around this clang bug by ignoring '#if __has_extension(c_generic_selections)' when it succeeds. If clang is going to diagnose any use of an extension X, then __has_extension(X) should be false. Perhaps the clang folks could implement this suggestion. > The easiest workaround is to not use c99, but "cc -std=c11", optionally with "-pedantic", that will work just fine even with ce293ccb574a77956c758a81287dbc8ef4f4eedf reverted. You can do that by editing the "#CC = ..." line in the tzcode Makefile, or by running "make CC='cc -std=c11'". We can't make these changes in tzcode's distributed Makefile, though, as that wouldn't be portable. > In addition, -pedantic is known to complain about GNU extensions such as __builtin_offsetof. There is not much you can do about that, since we make extensive use of such extensions in the FreeBSD system headers. Yes, your email contained the following messages indicating this problem: > zic.c:2395:11: warning: defining a type within '__builtin_offsetof' is a Clang extension [-Wgnu-offsetof-extensions] > 2395 | alignof(zic_t))); > | ^~~~~~~~~~~~~~ > zic.c:74:33: note: expanded from macro 'alignof' > 74 | # define alignof(type) offsetof(struct { char a; type b; }, b) > | ^~~~~~ > /usr/include/stddef.h:71:42: note: expanded from macro 'offsetof' > 71 | #define offsetof(type, field) __offsetof(type, field) > | ^~~~ > /usr/include/sys/cdefs.h:424:53: note: expanded from macro '__offsetof' > 424 | #define __offsetof(type, field) __builtin_offsetof(type, field) > | ^~~~ I don't see this message in FreeBSD 14, so this is a regression in FreeBSD 15. And it appears to be another bug in FreeBSD and/or clang. First, any code using __builtin_offsetof is using a GNU extension, so why warn about __builtin_offsetof with a particular argument that happens to be a new type? And second, "__builtin_offsetof(struct { char a; type b; }, b)" doesn't define any type that can be used anywhere else, so why warn about the type? And third, there's nothing in C99 that prohibits the use of "offsetof(struct { char a; type b; }, b)" and it works on every C99 platform, so why warn about it? I reproduced the problem on Fedora 39 with "make CC='clang -std=iso9899:1999 -pedantic'", and attempted to pacify clang with the attached patch, but that merely changed the diagnostics to be something like this: zic.c:2408:11: warning: '_Alignof' is a C11 extension [-Wc11-extensions] 2408 | alignof(zic_t))); | ^ /usr/bin/../lib/clang/17/include/stdalign.h:19:17: note: expanded from macro 'alignof' 19 | #define alignof _Alignof | ^ 1 warning generated. Since this bug is only a warning, perhaps we should give up trying to work around it. I hope the clang folks fix the bug eventually.

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Re: [tz] Antarctic research base Vostok local time
by Paul Eggert Dec. 21, 2023

Dec. 21, 2023

On 2023-12-18 19:14, АПС АКУЛОВ wrote: > >Do you have a public announcement on the web, or some other source, > that we can cite? > Well AARI weekly publishes Antarctic events summaries here: > https://www.aari.ru/press-center/news/rae . > > But I am not sure if my case will be mentioned there. This web page still says that Vostok time is UTC+07: https://www.aari.ru/ekspeditsii/rossiyskaya-antarkticheskaya-ekspeditsiya-(… Could you please fix that web page? That would help confirm the change, so that when people ask us for our source, we can direct them to aari.ru. > >Does "00:00" mean 00:00 local time, or 00:00 UTC? > > My bad, sorry, I missed this point. > > Local time, of source. OK. Did clocks jump back from 00:00 today to 22:00 the previous day, or from 02:00 to 00:00 today? Also, could you please briefly say why Vostok changed from UTC+07 to UTC+05? I would like to document this in commentary. > >Has local time at Vostok been UTC+6 ever since 1957, or has it changed > before? > > No. At least since my antarctic career start, 10 years ago, Vostok base > has UTC+7. Ouch. TZDB has been wrong for Vostok for at least 10 years. I will try to correct this. (I hope you have not been at Vostok for 10 years! I'd rather live in Siberia, or even in Nebraska. I can joke about this, as I was born in Nebraska....) Attached is a draft patch to TZDB to implement these changes. Please let us know if you see problems with it. I have not installed this patch into the TZDB development repository as it is still preliminary.

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[PROPOSED] * zonenow.tab: Fix Troll DST offset in comment.
by Paul Eggert Dec. 20, 2023

Dec. 20, 2023

--- zonenow.tab | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/zonenow.tab b/zonenow.tab index c03e0bba..aea2a90e 100644 --- a/zonenow.tab +++ b/zonenow.tab @@ -132,7 +132,7 @@ XX +513030-0000731 Europe/London United Kingdom ("GMT/BST") # +00/+01 - WET/WEST (EU DST) XX +3843-00908 Europe/Lisbon western Europe ("WET/WEST") # -# +00/+01 - Troll DST +# +00/+02 - Troll DST XX -720041+0023206 Antarctica/Troll Troll Station in Antarctica # # +01 - CET -- 2.43.0

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[PROPOSED 00/18] tzselect improvements for configuring "from now on"
by Paul Eggert Dec. 20, 2023

Dec. 20, 2023

For some time I've been meaning to extend tzselect so that users who care only about timestamps from now on can have a smaller set of timezones to choose from, thus simplifying configuration. This patchset does this via a new file zonenow.tab, with contents like zone1970.tab except that zonenow.tab partitions based on timestamps from now on, instead of from 1970 on. The new file's format is still experimental and feedback is welcome. These patches mostly just refactor tzselect, to simplify support for the new feature. The last patch adds the new feature. Paul Eggert (18): More-systematic punctuation in *.tab comments Improve Canadian comments in zone*.tab Open /dev/null less often in tzselect * Makefile: Say that ‘make’ should conform to POSIX. Improve tzselect diagnostics after rejection Don’t set TZ in tzselect Do not use empty RE in tzselect Port to POSIX awk, which prohibits -v newlines tzselect: work around mawk bug with {2,} * tzselect: Improve leading comments. tzselect: clarify translit need tzselect: port to POSIX iconv * NEWS: Improve formatting of tzselect news. tzselect: do not create temporary files * tzselect: Indent more consistently. * tzselect.ksh: Consistently omit ‘;;’ before ‘esac’. * tzselect.ksh: Indent more consistently. New tzselection option ‘now’ Makefile | 34 +- NEWS | 28 +- checknow.awk | 53 +++ checktab.awk | 7 +- tzselect.ksh | 977 ++++++++++++++++++++++++++++----------------------- zone.tab | 24 +- zone1970.tab | 24 +- zonenow.tab | 298 ++++++++++++++++ 8 files changed, 978 insertions(+), 467 deletions(-) create mode 100644 checknow.awk create mode 100644 zonenow.tab -- 2.40.1

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[PROPOSED 0/9] Fixes for Casey and for portability
by Paul Eggert Dec. 20, 2023

Dec. 20, 2023

Most of these fixes are so that ‘make check’ passes, or improve commentary. The more noticeable changes are to the Antarctica/Casey data (where there’s a good chance we’re still wrong but at least we’re more in sync with timeanddate.com) along with code portability fixes for FreeBSD and OpenBSD. Paul Eggert (9): Distribute new file checknow.awk too Fix ‘make check_character_set’ false positive Update tzselect comment for Solaris 10 EOL * checknow.awk: Fix typo in empty-input diagnostic. Port ‘make check_now’ to macOS Pacify FreeBSD 14 c99 Sync Casey data from timeanddate.com Port localtime.c timeoff to OpenBSD 7.4 * NEWS: Mention a few more post-2023c changes. Makefile | 27 ++++++++++++++++----------- NEWS | 13 +++++++++++++ antarctica | 12 +++++++++++- checknow.awk | 3 ++- localtime.c | 3 +++ private.h | 4 +--- tzselect.ksh | 2 +- 7 files changed, 47 insertions(+), 17 deletions(-) -- 2.43.0

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Re: [tz] leap_second.list not updated after latest IERS Bulletin C
by Paul Eggert Dec. 19, 2023

Dec. 19, 2023

On 12/7/23 13:21, Geert Hendrickx wrote: > NTPsec logs the following at startup: > > CLOCK: leapsecond file ('/etc/ntp/leap-seconds.list'): good hash signature > > CLOCK: leapsecond file ('/etc/ntp/leap-seconds.list'): loaded, expire=2024-06-28T00:00Z last=2017-01-01T00:00Z ofs=37 > > > So I *guess* (without having looked at the code) that it actually cares > about the expiration date as well. I think you're right NTPsec does care, though I vaguely recall that if the file has expired the only issue is an unwanted log message. If people are running NTPsec and configuring it to use TZDB's leap-seconds.list, that unwanted log message could be an issue. I just now checked the NTPsec source code, though, and by default it uses this URL: https://www.ietf.org/timezones/data/leap-seconds.list which hasn't worked in a while; the contents are simply "ietf.org is no longer serving this file." So it may be that we don't need to issue a new TZDB release merely because 2023c's leap-seconds.list will be out-of-date soon. > (but we periodically download it from IERS, not from TZ) In that case your setup is OK as-is, though we may still need to hear from other people to see whether they're relying on the TZDB copy of leap-seconds.list. TZDB uses the NIST version of leap-seconds.list rather than the IERS version, as the NIST version is clearly public domain and so this way we don't have to worry about copyright issues. However, the IERS version should work fine with either NTPsec or with other downstream uses, such as TZDB itself (that is, if you're not worried about copyright).

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Antarctic research base Vostok local time
by АПС АКУЛОВ Dec. 18, 2023

Dec. 18, 2023

Pse be informed that from December, 18, 2023 00:00 by my decision the local time of the Antarctic research base Vostok will correspond to UTC+5. Sincerely, Chief of Antarctic research base Vostok, Zakhary V. Akulov -- УВАЖЕНИЕМ= АПС АКУЛОВ= 69 РАЭ СТ ВОСТОК-

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[BUG] Expression is always zero
by RekGRpth Dec. 14, 2023

Dec. 14, 2023

The value of expression 'thistimecnt >> 31 >> 31 >> 2' (in zic.c) is zero regardless of the value of the left operand 'thistimecnt', because it is shifted by 64 (in total) bits, which is greater or equal to its size of 64 bits. Maybe this was what was meant? thistimecnt >> 31 >> 2

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Tab/Space Formatting Inconsistency - Asia Ver 2023c
by Gary Cho Dec. 12, 2023

Dec. 12, 2023

Hello, While writing software to parse through the database, I found the following inconsistencies in the "asia" file 1) Line 3463 to 3569 - Rule should be followed by a tab instead of a space 2) Line 3587 ,3589,3591,3593 - STDOFF should be followed by a tab instead of space 3) Line 3096 - STDOFF should be followed by a tab instead of space Gary Cho

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leap_second.list not updated after latest IERS Bulletin C
by Maximilian Linhoff Dec. 11, 2023

Dec. 11, 2023

Dear IANA Timezone People, The latest leap_seconds.lst file you provide here: https://data.iana.org/time-zones/tzdb/leap-seconds.list and the other related files were last updated 2023-03-28. The leap second table has an expiry date of 2023-12-28, which is rapidly approaching. There is IERS Bulletin C from 2023-07-04 announcing no new leap second on 2023-12-31, so the expiry date of the list can be updated to 2023-06-28. Kind regards Maximilian Linhoff -- Dr. Maximilian Linhoff PostDoc Astroteilchenphysik Technische Universität Dortmund Fakultät Physik / Astroteilchenphysik Otto-Hahn-Str. 4a 44227 Dortmund Tel.: +49 231 755 8895 maximilian.linhoff(a)tu-dortmund.de https://app.tu-dortmund.de

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Re: [tz] leap_second.list not updated after latest IERS Bulletin C
by Hal Murray Dec. 7, 2023

Dec. 7, 2023

Paul Eggert said: > Is there some reason we need a new TZDB release because of this? Do you use > software that requires that this file come from a TZDB release, rather than > from other sources such as the one mentioned above? Yes, NTP can use the leap file from other sources. The idea of distributing it with TZDB is that it removes an operational step from running NTP with (hopefully) minimal work on the TZ team and OS distros since they are already distributing TZ info. Debian's ntpsec.conf now contains: leapfile /usr/share/zoneinfo/leap-seconds.list > I recall that traditionally ntpd needed leap-seconds.list and looked at the > expiration but am not up to date with what its successor NTPsec is doing. NTPsec uses the expiration date. Long version: GPS satellites distribute leap second info. Some receivers pass that on to the clients. So does NIST's ACTS phone/modem time service. WWVB in US, JJY in Japan, MSF in UK, and DCF77 in Germany also provide leap second info. I'm not sure how many receivers make that available. NTP can get leap info from 3 sources: file, radio, and network. If it has a valid file, it believes that. If it doesn't have a file, next in line is a local refclock. With no file and no refclocks, it gets leap info from network time servers. So a valid file when there is no leap pending will keep ntpd from believing buggy or malicious NTP servers on the net. I think there was an event where a bunch of servers didn't stop advertising a leap. It was many years ago. I've forgotten the details. I think the code was changed from believing one server to requiring a majority. There is a subtle difference between no-known-leap and known-no-leap. The NTP packet format doesn't have a way to indicate known-no-leap and that gap probably percolates through the code. It may not actually work as I described above but that's the way it should work. -- These are my opinions. I hate spam.

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If leap seconds go away, should TZif leap-second tables expire?
by Paul Eggert Nov. 29, 2023

Nov. 29, 2023

I have a question about leap-second table expiration in TZif files. Please bear with a longish explanation first; the actual question is at the end of this message. Since release 2020a, TZDB's zic command has supported "Expires" lines in the leapseconds file, and has propagated that info to TZif files using an extension to Internet RFC 8536. This extension is a bit of a hack: if a TZif file's last leap-second record has the same correction as the penultimate record, then the last record is the leap second expiry. For example, if the file 'leap-seconds.list' contains the line: #@ 3928521600 which stands for 28 June 2024; and if you run the command 'make EXPIRES_LINE=1 leapseconds', the file 'leapseconds' will contain: Expires 2024 Jun 28 00:00:00 and if you then run 'make install', the resulting TZif files with leap seconds will contain two leap transitions with correction 27, one transition for 1483228826 (representing 2016-12-31 23:59:60 UTC, the most recent leap second), and one transition for 1719532827 (representing 2017-06-28 00:00:00 UTC, the leap second table expiration). This Expires-line feature was introduced to TZDB in release 2020a, replacing an older hack using an "#expires" comment. However, in the interest of stability the feature has been disabled by default and you must use a non-default setting like "make EXPIRES_LINE=1" to enable it. Our current draft -09 revision to Internet RFC 8536 documents this new feature for the planned version 4 of the TZif file. See <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/09/> section 3.2 item "corr(ection)", which says: "... in version 4 files with two or more leap-second records, the correction value of the last two records MAY be the same, with the occurrence of last record indicating the expiration time of the leap-second table." "The leap-second table expiration time is the time at which the table no longer records the presence or absence of future leap- second corrections, and post-expiration timestamps can not be accurately calculated. For example, a leap-second table published in January, which predicts the presence or absence of a leap second at June's end, might expire in mid-December because it is not known whether a leap second will occur at December's end. To complicate matters, a year ago the General Conference on Weights and Measures adopted a resolution calling for leap seconds to be phased out by 2035 <https://www.bipm.org/en/cgpm-2022/resolution-4>. If this is indeed done as late as possible there's a chance we could have our first-ever negative leap second before 2035 <https://insidegnss.com/will-we-have-a-negative-leap-second/> which could cause software havoc, and it's not clear whether the authorities would go through with this. One more thing: the World Radio Conference is currently meeting in Dubai and this meeting may take further action regarding leap seconds. Draft -09 currently has the following text about the possible impending demise of leap seconds: "If leap seconds become permanently discontinued, as requested by the General Conference on Weights and Measures [CGPM-2022-R4], leap-second tables published after the discontinuation time SHOULD NOT expire, since they will not be updated in the foreseeable future." With all the above in mind, here is my question. Should TZif leap-second tables have no expiration date if leap seconds are discontinued, as draft -09 suggests? Or should they have an expiration date of (say) January 2100, which is likely a lower bound on the date that the leap-second regime would be replaced by some other regime, such as leap minutes? Or should we do something else about TZif leap-second expiry after leap seconds are discontinued?

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Re: [tz] If leap seconds go away, should TZif leap-second tables expire?
by Hal Murray Nov. 29, 2023

Nov. 29, 2023

Paul Eggert said: > Should TZif leap-second tables have no expiration date if leap seconds are > discontinued, as draft -09 suggests? Or should they have an expiration date > of (say) January 2100, which is likely a lower bound on the date that the > leap-second regime would be replaced by some other regime, such as leap > minutes? Or should we do something else about TZif leap-second expiry after > leap seconds are discontinued? I suggest waiting. Everybody else is going to have the same problem. As part of working out the no-leap details, somebody will have to pick a value so they can say something like "we won't have any leaps for the next N years". Then you can plug that number in. -- These are my opinions. I hate spam.

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Re: [tz] localtime crash and fix
by Alois Treindl Nov. 28, 2023

Nov. 28, 2023

Thanks for fixing. I still find the code unnecessarily obscure due to the use of two unions stacked inside each other. > /* Input buffer for data read from a compiled tz file. */ > union input_buffer { > /* The first part of the buffer, interpreted as a header. */ > struct tzhead tzhead; > > /* The entire buffer. */ > char buf[2 * sizeof(struct tzhead) + 2 * sizeof(struct state) > + 4 * TZ_MAX_TIMES]; > }; > > /* TZDIR with a trailing '/' rather than a trailing '\0'. */ > static char const tzdirslash[sizeof TZDIR] = TZDIR "/"; > > /* Local storage needed for 'tzloadbody'. */ > union local_storage { > /* The results of analyzing the file's contents after it is opened. */ > struct file_analysis { > /* The input buffer. */ > union input_buffer u; > > /* A temporary state used for parsing a TZ string in the file. */ > struct state st; > } u; > > /* The file name to be opened. */ > char fullname[max(sizeof(struct file_analysis), sizeof tzdirslash + 1024)]; > }; The size of local_starage is in the range of 80 kb, not exactly something for a "small stack". The element buf is rather large. I think you save only 1kb extra spece for fullname, and some 30 bytes for tzhead. I do not think that these very minor saving justify the obscurity introduced in the code. It makes it hard to read and hard to debug. Please consider that others want to understand tzcode also. > Am 24.11.2023 um 23:14 schrieb Paul Eggert <eggert(a)cs.ucla.edu>: > > On 2023-11-24 08:22, Alois Treindl via tz wrote: >> The use of union to save memory is dangerous, in my opinion. There is no need in today's machines to save a few kilobytes of RAM for a process. >> Not even in embedded software for watches. > > When the memory is on the stack it still makes sense in some cases to save even a few kilobytes of RAM, as highly-threaded apps often have surprisingly small stacks. And anyway, the union has nothing to do with this particular bug.

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[PROPOSED] Fix zic bug with -r @X where X is deduced from TZ
by Paul Eggert Nov. 27, 2023

Nov. 27, 2023

Problem reported by Ken Murchison for ‘zic -b slim -r @2145916800 asia’, which generated an Asia/Jerusalem TZif file with a single transition from -00 to IDT at 2145916800 (2038-01-01 00:00:00 UTC). The transition should be to IST. * NEWS: Mention this. * zic.c (main): Don’t let redundant_time be lower than lo_time. (outzone): Fix code for omitting trailing transitions when -R is specified, which was inadvertently messed up by the 2023-10-15 fix for Palestine after 2075. --- NEWS | 3 ++- zic.c | 15 +++++++++++---- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/NEWS b/NEWS index 0d7fde80..c07cc7ad 100644 --- a/NEWS +++ b/NEWS @@ -37,7 +37,8 @@ Unreleased, experimental changes zic no longer mishandles data for Palestine after the year 2075. Previously, it incorrectly omitted post-2075 transitions that are - predicted for just before and just after Ramadan. + predicted for just before and just after Ramadan. (Thanks to Ken + Murchison for debugging help.) zic now works again on Linux 2.6.16 and 2.6.17 (2006). (Problem reported by Rune Torgersen.) diff --git a/zic.c b/zic.c index e10cb21b..b260851f 100644 --- a/zic.c +++ b/zic.c @@ -897,7 +897,8 @@ static zic_t const max_time = MAXVAL(zic_t, TIME_T_BITS_IN_FILE); static zic_t lo_time = MINVAL(zic_t, TIME_T_BITS_IN_FILE); static zic_t hi_time = MAXVAL(zic_t, TIME_T_BITS_IN_FILE); -/* The time specified by the -R option, defaulting to MIN_TIME. */ +/* The time specified by the -R option, defaulting to MIN_TIME; + or lo_time, whichever is greater. */ static zic_t redundant_time = MINVAL(zic_t, TIME_T_BITS_IN_FILE); /* The time specified by an Expires line, or negative if no such line. */ @@ -1109,6 +1110,8 @@ main(int argc, char **argv) fprintf(stderr, _("%s: -R time exceeds -r cutoff\n"), progname); return EXIT_FAILURE; } + if (redundant_time < lo_time) + redundant_time = lo_time; if (bloat == 0) { static char const bloat_default[] = ZIC_BLOAT_DEFAULT; if (strcmp(bloat_default, "slim") == 0) @@ -3442,6 +3445,9 @@ outzone(const struct zone *zpfirst, ptrdiff_t zonecount) if (defaulttype < 0) defaulttype = 0; if (!do_extend && !want_bloat()) { + /* Keep trailing transitions that are no greater than this. */ + zic_t keep_at_max; + /* The earliest transition into a time governed by the TZ string. */ zic_t TZstarttime = ZIC_MAX; for (i = 0; i < timecnt; i++) { @@ -3452,10 +3458,11 @@ outzone(const struct zone *zpfirst, ptrdiff_t zonecount) if (TZstarttime == ZIC_MAX) TZstarttime = nonTZlimtime; - /* Omit trailing transitions deducible from the TZ string. */ + /* Omit trailing transitions deducible from the TZ string, + and not needed for -r or -R. */ + keep_at_max = max(TZstarttime, redundant_time); for (i = j = 0; i < timecnt; i++) - if (redundant_time <= attypes[i].at - && attypes[i].at <= TZstarttime) { + if (attypes[i].at <= keep_at_max) { attypes[j].at = attypes[i].at; attypes[j].dontmerge = (attypes[i].at == TZstarttime && (nonTZlimtype != attypes[i].type -- 2.40.1

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[PROPOSED 1/4] Fix bug with ‘make typecheck; make clean’
by Paul Eggert Nov. 25, 2023

Nov. 25, 2023

* Makefile (clean_misc): Also remove typecheck_*.dir. --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 8df3b621..edbc4d16 100644 --- a/Makefile +++ b/Makefile @@ -944,7 +944,7 @@ check_zishrink_posix check_zishrink_right: \ touch $@ clean_misc: - rm -fr check_*.dir + rm -fr check_*.dir typecheck_*.dir rm -f *.o *.out $(TIME_T_ALTERNATIVES) \ check_* core typecheck_* \ date tzselect version.h zdump zic libtz.a -- 2.40.1

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Re: [tz] localtime crash and fix
by Alois Treindl Nov. 24, 2023

Nov. 24, 2023

That is effectively the same. But I would rather if Paul Eggert fixed the code. When I diff localtime.c from 2023c release with the current github version, there are changes which are obscure to me. The use of union to save memory is dangerous, in my opinion. There is no need in today's machines to save a few kilobytes of RAM for a process. Not even in embedded software for watches. It makes the code obscure. I have the gut feeling that the bug is in the line sp->goahead = ts->goahead; where ts has inherited old data from a previous call. On 24.11.23 16:54, Carlo wrote: > Dear Alois > > > Have you tried using this, letting the compiler perform the memset: > > #else > union local_storage ls = {0}; > return tzloadbody(name, sp, doextend, &ls); > #endif > > On Thu, Nov 23, 2023 at 7:32 PM Alois Treindl via tz <tz(a)iana.org> wrote: > > I have observed occasional crashes in localtime.c in the current > github version. > > In one of my applications, localtime() is called multiple times > for several zones. > > The condition when the segmentation fault appears are herd to > reproduce or demonstrate. > > This patch in function tzload() however solves the issue: > > --- localtime.c 2023-11-16 20:18:01.904577574 +0100 > +++ a/localtime.c 2023-11-23 19:22:21.062249899 +0100 > @@ -769,6 +769,7 @@ > } > #else > union local_storage ls; > + memset(&ls, 0, sizeof(ls)); > return tzloadbody(name, sp, doextend, &ls); > #endif > } >

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localtime crash and fix
by Alois Treindl Nov. 24, 2023

Nov. 24, 2023

I have observed occasional crashes in localtime.c in the current github version. In one of my applications, localtime() is called multiple times for several zones. The condition when the segmentation fault appears are herd to reproduce or demonstrate. This patch in function tzload() however solves the issue: --- localtime.c 2023-11-16 20:18:01.904577574 +0100 +++ a/localtime.c 2023-11-23 19:22:21.062249899 +0100 @@ -769,6 +769,7 @@ } #else union local_storage ls; + memset(&ls, 0, sizeof(ls)); return tzloadbody(name, sp, doextend, &ls); #endif }

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Did Greenland abolish daylight saving from 2024 on?
by Paul Eggert Nov. 20, 2023

Nov. 20, 2023

This week several English-language news sources reported that Greenland has moved its clocks forward for the last time. These reports disagree with current TZDB[1], which follows Thomas M. Steenholdt's December email[2] saying that although in November Greenlanders voted to not fall back this fall, they also voted to continue to observe daylight saving time (DST) next year, effectively moving their time zone one hour east instead of abolishing DST. There's no disagreement about timekeeping this year. The first point of disagreement is March 30, 2024 at 23:00, when TZDB says Nuuk, Greenland will spring forward to 24:00, whereas the recent news reports say clocks will neither spring forward nor fall back during 2024. So who's right: Steenholdt in December, or these several recent news reports? Currently TZDB goes with Steenholdt. After all, he cited the relevant Greenland legislation and his email address ends in ".gl". I suppose another possibility, though, is that Greenland's government has changed its mind since November. However, if so I'd like to see citations to the newer legislation. The earliest recent news story I found on this topic was a week ago by Lebawit Lily Girma[3], senior travel news reporter for Bloomberg Pursuits. I'm taking the liberty of bcc'ing Girma to see if she can help get to the bottom of the situation. [1]: https://iana.org/tz [2]: https://mm.icann.org/pipermail/tz/2022-December/032402.html [3]: Girma LL. Greenland Solves the Daylight Saving Time Debate. Bloomberg. 2023-03-24. https://www.bloomberg.com/news/articles/2023-03-24/greenland-keeps-daylight… Here are some of the other news reports I found. Greenland to stay in daylight saving time forever. AP. 2023-03-27. https://apnews.com/article/greenland-daylight-saving-summertime-utc-gmt-3b5… Martin M. Greenland is keeping daylight saving time permanently. NPR. 2023-03-28. https://www.wunc.org/2023-03-28/greenland-is-keeping-daylight-saving-time-p… Selcho M. Here’s why Greenland is permanently keeping daylight saving time. Deseret News. 2023-03-28. https://www.deseret.com/u-s-world/2023/3/28/23660379/why-greenland-keeping-… Jerusalem Post staff. Greenland changed their clocks to daylight savings for the last time. Jerusalem Post. 2023-03-29. https://www.jpost.com/international/article-735751 Carpineti A. Greenland Has Changed Its Clocks For The Last Time, Embracing Daylight Savings Forever. IFLScience. 2023-03-29. https://www.iflscience.com/greenland-has-changed-its-clocks-for-the-last-ti…

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make error
by Alois Treindl Nov. 20, 2023

Nov. 20, 2023

I just made a new clone of tz. I work normally on RHEL 7 (redhat enterprise Linux) with gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC) When I say make or make all, I get something I never observed before: cc -DTZDIR='"/usr/share/zoneinfo"' -c -o zic.o zic.c In file included from zic.c:16:0: private.h:791:60: error: conflicting types for ‘restrict’ struct tm *localtime_rz(timezone_t restrict, time_t const *restrict, ^ private.h:791:36: note: previous definition of ‘restrict’ was here struct tm *localtime_rz(timezone_t restrict, time_t const *restrict, ^ private.h:792:15: error: conflicting types for ‘restrict’ struct tm *restrict); ^ private.h:791:60: note: previous definition of ‘restrict’ was here struct tm *localtime_rz(timezone_t restrict, time_t const *restrict, ^ private.h:793:49: error: conflicting types for ‘restrict’ time_t mktime_z(timezone_t restrict, struct tm *restrict); ^ private.h:793:28: note: previous definition of ‘restrict’ was here time_t mktime_z(timezone_t restrict, struct tm *restrict); This does not happen when I compile on RHEL 9 gcc version 11.4.1 20230605 (Red Hat 11.4.1-2) (GCC) Can anyone point me to a fix?

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