[tz-announce] 2022b release of tz code and data available

Aug. 11, 2022

      The 2022b release of the tz code and data is available.

This release reflects the following changes:

   Briefly:
     Chile's DST is delayed by a week in September 2022.
     Iran no longer observes DST after 2022.
     Rename Europe/Kiev to Europe/Kyiv.
     New zic -R option
     Vanguard form now uses %z.
     Finish moving duplicate-since-1970 zones to 'backzone'.
     New build option PACKRATLIST
     New tailored_tarballs target, replacing rearguard_tarballs

   Changes to future timestamps

     Chile's 2022 DST start is delayed from September 4 to September 11.
     (Thanks to Juan Correa.)

     Iran plans to stop observing DST permanently, after it falls back
     on 2022-09-21.  (Thanks to Ali Mirjamali.)

   Changes to past timestamps

     Finish moving to 'backzone' the location-based zones whose
     timestamps since 1970 are duplicates; adjust links accordingly.
     This change ordinarily affects only pre-1970 timestamps, and with
     the new PACKRATLIST option it does not affect any timestamps.
     In this round the affected zones are Antarctica/Vostok,
     Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
     Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
     Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
     Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
     Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
     Pacific/Wake and Pacific/Wallis, and the affected links are
     Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
     Pacific/Truk, and Pacific/Yap.

     From fall 1994 through fall 1995, Shanks wrote that Crimea's
     DST transitions were at 02:00 standard time, not at 00:00.
     (Thanks to Michael Deckers.)

     Iran adopted standard time in 1935, not 1946.  In 1977 it observed
     DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
     03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
     transition was on 05-27, not 03-21.
     (Thanks to Roozbeh Pournader and Francis Santoni.)

     Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
     considered DST, not standard time.  Santiago and environs had moved
     their clocks back to rejoin the rest of mainland Chile; put this
     change at the end of 1946-08-28.  (Thanks to Michael Deckers.)

     Some old, small clock transitions have been removed, as people at
     the time did not change their clocks.  This affects Asia/Hong_Kong
     in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.

   Changes to zone name

     Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
     English now.  Spelling of other names in Ukraine has not yet
     demonstrably changed in common English practice so for now these
     names retain old spellings, as in other countries (e.g.,
     Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").

   Changes to code

     zic has a new option '-R @N' to output explicit transitions < N.
     (Need suggested by Almaz Mingaleev.)

     'zic -r @N' no longer outputs bad data when N < first transition.
     (Problem introduced in 2021d and reported by Peter Krefting.)

     zic now checks its input for NUL bytes and unterminated lines, and
     now supports input line lengths up to 2048 (not 512) bytes.

     gmtime and related code now use the abbreviation "UTC" not "GMT".
     POSIX is being revised to require this.

     When tzset and related functions set vestigial static variables
     like tzname, they now prefer specified timestamps to unspecified
     ones.  (Problem reported by Almaz Mingaleev.)

     zic no longer complains "can't determine time zone abbreviation to
     use just after until time" when a transition to a new standard
     time occurs simultanously with the first DST fallback transition.

   Changes to build procedure

     Source data in vanguard form now uses the %z notation, introduced
     in release 2015f.  For example, for America/Sao_Paulo vanguard
     form contains the zone continuation line "-3:00 Brazil %z", which
     is simpler and more reliable than the line "-3:00 Brazil -03/-02"
     used in main and rearguard forms.  The plan is for the main form
     to use %z eventually; in the meantime maintainers of zi parsers
     are encouraged to test the parsers on vanguard.zi.

     The Makefile has a new PACKRATLIST option to select a subset of
     'backzone'.  For example, 'make PACKRATDATA=backzone
     PACKRATLIST=zone.tab' now generates TZif files identical to those
     of the global-tz project.

     The Makefile has a new tailored_tarballs target for generating
     special-purpose tarballs.  It generalizes and replaces the
     rearguard_tarballs target and related targets and macros, which
     are now obsolescent.

     'make install' now defaults LOCALTIME to Factory not GMT,
     which means the default abbreviation is now "-00" not "GMT".

     Remove the posix_packrat target, marked obsolescent in 2016a.

Here are links to the release files:

   https://www.iana.org/time-zones/repository/releases/tzcode2022b.tar.gz
   https://www.iana.org/time-zones/repository/releases/tzdata2022b.tar.gz
   https://www.iana.org/time-zones/repository/releases/tzdb-2022b.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 
b61a7acb4d267872f1c5319f30889a927b441b8f dated 2022-08-10 15:38:32 -0700 
and tagged '2022b' in the development GitHub repository at 
<https://github.com/eggert/tz>.

Here are the SHA-512 checksums for the release files:

851622eb8e6dc8f8201bf05e1f7e411ca32b2ed0f4dc9f6b875f4482c05c4a3302259b78c3e8e2dadda52ae19d4d34ffa3463fee10f70fa3a8b08b19f1417f79 
  tzcode2022b.tar.gz
a51418cda50386bc2e82a26201178c282ec225e04867e70a47ef90f42371a4014c70bffebb52ac09ccd893dfa17b0acc782f31527b3579ebdc4a302a9367ddb1 
  tzdata2022b.tar.gz
b5bd93401c9586047e865a49b9f7fd0bdf451973be24a433786633f41a1ecc2f7eacdeb78d9a906c3526bfd3b236edab72682e5bc09add42156f8dcc2497694a 
  tzdb-2022b.tar.lz

Here are the GPG digital signatures for the release files:

PS. If your tzdata parser does not yet support negative DST offsets or 
times past 24:00, or if it insists on a 'pacificnew' file that is no 
longer present, this release's data entries can be turned into a 
rearguard-format tarball that should work even with these older parsers. 
This is intended to be a temporary transition aid for these parsers. To 
generate a rearguard-format tarball, obtain the full distribution as 
described above, and run the command 'make DATAFORM=rearguard 
tailored_tarballs' on a development host. Or you can run 'make 
rearguard.zi' to generate a single file that can be fed directly to a 
parser that works like 'zic'.

[tz-announce] 2022b release of tz code and data available

Paul Eggert