Date: Tue, 28 Nov 2023 23:31:18 -0800 From: Paul Eggert via tz <tz@iana.org> Message-ID: <b1216f8c-8fc6-433d-b4da-c8a3f47db402@cs.ucla.edu> | Should TZif leap-second tables have no expiration date if leap seconds | are discontinued, as draft -09 suggests? I don't think TZif files should have a leap second expiration date at all, nor should there be any kind of transition at that point. I have always interpreted the expiration date in the bulletins as applying to the bulletins themselves, not to the leap seconds they advise about. That's why it makes no sense to continus having an expiration date in the bulletin if leap seconds are discontinued. Otherwise a new bulletin would still need to be issued every 6 months, all saying that no leap seconds were being added or deleted during the validity of the bulletin. The expiration date that currently exists allows readers to determine if the bulletin they're reading contains valid data, or if it is obsolete, and they should go get a newer one - that's all. Future data in TZif files is always just a guess, it might make some sense to have data in their indicatinh the time up until when we believe the data is reliable (more or less the publication date - lder data might have errors, but those are errors, ie": bugs, rather than unavoidable). That might help people determine if they want to go look for newer data, but unless you want to commit to always issuing a new release periodically. even if nothing has changed, it cannot really be an expiration date, just a hint. What do you believe this field in the TZif files is useful for now? kre