[tz] changes to the TZ database over versions
apb at cequrux.com
Sun Jun 1 16:30:57 UTC 2014
On Sun, 01 Jun 2014, Joris Van den Bogaert wrote:
> Looking at the git log, it looks like most changes are typos and
> adjustments to data far away in the past, like the early 1900's
> or Big Bang :) changes and sometimes the very near future, like
> Egypt and Turkey.
> I didn't find any substantial changes that were made in the near
There are occasionally changes that affect the recent past, such
as when governments make changes with very short notice. It is
sometimes the case that the change has already taken effect in the
real world before the tz database is updated, or at least before
the new version is published and widely used.
> Hypothetically, let's say Catalonia becomes a separate state
> on 1/1/2015 and decides to have a timezone UTC+01:30 instead
> of CET. Do you guys then decide to create a new timezone
In that hypothetical situation, a new timezone would be created,
and named after the largest city or population centre in the
affected area, which could well be Barcelona.
> What (should) happens when converting the datetime 1/1/2014 with
> "Europe/Barcelona", a timezone that didn't exist at that time?
Any hypothetical new Europe/Barcelona zone would attempt to
report the time as it was in the city of Barcelona at least as
far into the past as 1 Jan 1970 (or perhaps farther, if good
records exist), and as far into the future as can reasonably be
predicted from legislation and other sources. So 1 Jan 2014 in a
hypothetical new Europe/Barcelone zone would be identical to 1 Jan
2014 in the existing Europe/Madrid zone.
--apb (Alan Barrett)
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