[tz] What data should TZDB offer?

Tom Lane tgl at sss.pgh.pa.us
Sun Jun 6 17:31:06 UTC 2021

Fred Gleason via tz <tz at iana.org> writes:
> On Jun 6, 2021, at 11:02, Tom Lane via tz <tz at iana.org> wrote:
>> The idea of having at least one zone per ISO-3166-1 country does
>> seem like a good one, though.

> These two points in particular are synergistic; stability of historical data is just a Good Thing, but no one here wants to see the TZDB maintainer receiving ‘vitriolic’ e-mail, nor getting sued [again]. Hence, politically ‘future-proofing' the DB seems a prudent move.

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.  If that initial data later
proves wrong, well, fixing it falls within longstanding tzdb practice.
But we shouldn't start out a new zone with known-bogus old data.
As an example that relates to one of the current complaints, if
Sweden had been part of the Europe/Berlin zone all along, we'd not
split out Europe/Stockholm without first reconstructing plausible
historical data for Sweden.

The advantage of this rule is that it would encourage an incremental
approach to getting to zone-per-country.  If someone comes along and
whines that $wherever should have its own zone, they can be told
"Sure.  Come back when you've done the research."  There's no reason
that Paul and Tim should be expected to make that happen on their own.

			regards, tom lane

More information about the tz mailing list