[tz] What data should TZDB offer?

John Hawkinson jhawk at alum.mit.edu
Sun Jun 6 17:56:25 UTC 2021

Tom Lane via tz <tz at iana.org> wrote on Sun,  6 Jun 2021
at 13:31:06 EDT in <655997.1623000666 at sss.pgh.pa.us>:

> I had a further thought about this: if we want to have both of these
> principles (zone-per-country and stability of old data), then it would
> make sense to insist that we don't create new per-country zones until
> someone has done the research to fill in plausible old data back to
> the LMT era for the proposed zone name.

I don't think this is correct or fair.

It's not correct because if there is a newly established zone (per-country or otherwise), early adopters of that zone can tolerate some flux in the data. It's not as if we're coming into an established zone with a lot of dependancies and expectations of stability. If the new zone goes in and today and the historical data comes a year later, that's probably OK. Not ideal, but OK. For sure we'd want to minimize adding it in fits and starts.

I don't think it's fair because the tz database needs to turn on a dime to reflect political changes that happen on rapid timescales. If a zone into two countries (whether by one of two previously-aligned countries changing their time zone rules, or by other political or even military mechanism) overnight, we need to push a new release out ASAP, we can't say, "oh, sorry, you can't have working time on your computers, we have to research the history, just suffer along for 6 months."

jhawk at alum.mit.edu
John Hawkinson

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