On 7/26/22 12:15, Guy Harris via tz wrote:
The only thing that gets in the way of this on macOS is that it doesn't ship the zic input files; you'd have to get them from https://opensource.apple.com/releases (select the release whose source files you want, and look for the version of the TimeZoneData project containing them.
Thanks for the pointer. I just looked at that URL, which pointed me to: https://github.com/apple-oss-distributions/TimeZoneData which pointed me to: https://github.com/apple-oss-distributions/TimeZoneData/tree/TimeZoneData-99... which has a tzdata2021a.tar.gz: https://github.com/apple-oss-distributions/TimeZoneData/raw/ffacbba48c11246d... Unfortunately I see nothing that says how this tar.gz file is used, which means it's unclear exactly which Zone lines are effective. So it'd be helpful if Apple installed a tzdata.zi file as you recently endorsed. Interestingly enough, Apple's tzdata2021a.tar.gz differs from upstream, which is here: https://ftp.iana.org/tz/releases/tzdata2021a.tar.gz in that Apple's uses rearguard format, and Apple's contains the file yearistype.sh which was removed in 2020b (and hadn't been used since 2000f). Other than yearistype.sh which should be irrelevant, Apple's tzdata2021a.tar.gz is identical to the tzdata2021a-rearguard.tar.gz generated by 'make rearguard_tarballs'. I guess that Apple names their file 'tzdata2021a.tar.gz' instead of 'tzdata2021a-rearguard.tar.gz' for some backward-compatibility reason (or perhaps they're embarrassed by the word "rearguard" :-).