[tz-announce] 2020b release of tz code and data available

Oct. 7, 2020

      The 2020b release of the tz code and data is available. It reflects the 
following changes, which were either circulated on the tz mailing list or are 
relatively minor technical or administrative changes:

   Briefly:
     Revised predictions for Morocco's changes starting in 2023.
     Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
     Macquarie Island has stayed in sync with Tasmania since 2011.
     Casey, Antarctica is at +08 in winter and +11 in summer.
     zic no longer supports -y, nor the TYPE field of Rules.

   Changes to future timestamps

     Morocco's spring-forward after Ramadan is now predicted to occur
     no sooner than two days after Ramadan, instead of one day.
     (Thanks to Milamber.)  The first altered prediction is for 2023,
     now predicted to spring-forward on April 30 instead of April 23.

   Changes to past and future timestamps

    Casey Station, Antarctica has been using +08 in winter and +11 in
    summer since 2018.  The most recent transition from +08 to +11 was
    2020-10-04 00:01.  Also, Macquarie Island has been staying in
    sync with Tasmania since 2011.  (Thanks to Steffen Thorsen.)

   Changes to past and future time zone abbreviations and DST flags

     Canada's Yukon, represented by America/Whitehorse and
     America/Dawson, changes its time zone rules from -08/-07 to
     permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
     This change affects only the time zone abbreviation (MST vs PDT)
     and daylight saving flag for the period between the two dates.
     (Thanks to Andrew G. Smith.)

   Changes to past timestamps

     Correct several transitions for Hungary for 1918/1983.
     For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
     (Thanks to Géza Nyáry.)  Also, the 1890 transition to standard
     time was on 11-01, not 10-01 (thanks to Michael Deckers).

     The 1891 French transition was on March 16, not March 15.  The
     1911-03-11 French transition was at midnight, not a minute later.
     Monaco's transitions were on 1892-06-01 and 1911-03-29, not
     1891-03-15 and 1911-03-11.  (Thanks to Michael Deckers.)

   Changes to code

     Support for zic's long-obsolete '-y YEARISTYPE' option has been
     removed and, with it, so has support for the TYPE field in Rule
     lines, which is now reserved for compatibility with earlier zic.
     These features were previously deprecated in release 2015f.
     (Thanks to Tim Parenti.)

     zic now defaults to '-b slim' instead of to '-b fat'.

     zic's new '-l -' and '-p -' options uninstall any existing
     localtime and posixrules files, respectively.

     The undocumented and ineffective tzsetwall function has been
     removed.

   Changes to build procedure

     The Makefile now defaults POSIXRULES to '-', so the posixrules
     feature (obsolete as of 2019b) is no longer installed by default.

   Changes to documentation and commentary

     The long-obsolete files pacificnew, systemv, and yearistype.sh have
     been removed from the distribution.  (Thanks to Tim Parenti.)

Here are links to the release files:

   https://www.iana.org/time-zones/repository/releases/tzcode2020b.tar.gz
   https://www.iana.org/time-zones/repository/releases/tzdata2020b.tar.gz
   https://www.iana.org/time-zones/repository/releases/tzdb-2020b.tar.lz

As usual, links to the latest release files are here:

   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 47311d42a3ad6a8afa95d1f63fa8b6bb2710b16e 
dated 2020-10-06 18:35:04 -0700 and tagged '2020b' in the development GitHub 
repository at <https://github.com/eggert/tz>.

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

04849f196430717962cbeedf11bbba592c304eaff5d67350c936af83dc8e8cb4cedc1c5f461c984aef05124d6c0f13a874789dff77b85a4b399faf80d75537e0 
  tzcode2020b.tar.gz
27ade698e61881e637ab04834633595cfbdb08fd97177e9731093165d1268a64dffa0570b5e137b9daa4374e6c6827ed01c476074ec61ec0b9a44a7f23479be9 
  tzdata2020b.tar.gz
475f69b908f8d7d777fcf93f1d223fc4af404a3c8caaa678ca97702a3e9c1ec3e1b5747c8688dfc7b291300bab9ff4804b8ceebfc2de47b505cffe4fa5594abc 
  tzdb-2020b.tar.lz

Here are the GPG checksums for the release files:

PS. If your tzdata parser does not yet support negative DST offsets or times 
past 24:00, this release's data entries can be turned into a rearguard-format 
tarball that does not use these features. 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 
rearguard_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] 2020b release of tz code and data available

Paul Eggert