[tz] Undoing the effect of the new alike-since-1970 patch

Stephen Colebourne scolebourne at joda.org
Wed Jun 9 21:41:56 UTC 2021

On Wed, 9 Jun 2021 at 21:13, Paul Eggert <eggert at cs.ucla.edu> wrote:
> Yes, I was definitely thinking of the comments. Also, the ordering of
> Zones (which is irrelevant). Stuff like that.

Neither comments nor ordering would be significant.

> > I've yet to see a willingness to engage on
> > backwards compatibility - to stop fiddling with the data.
> How about this: we could say that we won't do any sort of merging like
> this in the future. In other words, this is the last time we'll be
> merging legacy zones because they differ only before 1970. Would a
> statement like that help? We could put such a statement into the NEWS
> file, say.

It would be clearer to place an explicit statement in the charter or
theory file. That the TZDB co-ordinator will not merge timezones or
perform other actions that remove data from the database.

> > your patch (and probably previous ones) are
> > making a political statement of the kind you say you don't want.
> Sure, but no matter what we do we'll be making a political statement.
> The statement I'd like to see is "let's avoid political data when we
> can".

Country-based politics can be avoided by outsourcing the decision to
ISO-3166. When they recognise a country, a zone ID must also exist. It
is an incredibly simple rule, and easy for any drive-by commenters to

As Paul Ganssle says, the route you are trying to pursue really
doesn't make any logical sense because it is more work than putting
all the data in the main files and have the makefile perform a simple
filter by date. Once the premise is accepted that the backzone data is
a meaningful part of the project, there is literally no point in
retaining it in backzone (rather than europe or africa).

If you are willing to publish tarballs containing what is currently in
backzone, does that mean that it is now accepted that the backzone is
a valid and meaningful part of TZDB? That it can be enhanced if found
to be wrong? Like Paul Ganssle, I really think the line you are trying
to draw between the main files and backzone doesn't make any sense.

Once the premise that the data currently in backzone matters, it
should be restored to its rightful place in the main files, and
tooling used to merge zones (which would be consistent as opposed to
the piecemeal approach of the past few years.


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