[tz] Proposal to revert 2023b's Lebanon data changes

Howard Hinnant howard.hinnant at gmail.com
Mon Mar 27 21:11:44 UTC 2023

I’m not a Microsoft representative, however I do have data to add to such a discussion.

The C++20 language specification incorporates the IANA database into the C++ standard library.  On all platforms but Windows this is a fairly light weight lift because said platforms already ship with the IANA database.  Microsoft representatives agreed to this change in C++ and have implemented it by taking advantage of the IANA database that ships with ICU, which in turn ships on the latest Windows platforms.

The C++20 spec also has a “current time zone” function which must translate the Windows currently set time zone into an IANA time zone identifier.

I mention all this to reinforce Rich’s observation for the need for synchronization between these databases and to bring to attention additional motivations for such synchronization.


On Mar 27, 2023, at 4:35 PM, Rich Armstrong via tz <tz at iana.org> wrote:
> Though this list usually doesn't include discussion of the time-zone-rule data that Microsoft maintains in the Windows registry, it seems worth considering how to ensure the two repositories of time-zone rules might be kept in sync regarding the recent time change(s) in Lebanon-not to mention IATA's repository. Thoughts and opinions from any MS representatives would be welcome.

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