[tz] Dealing with Pre-1970 Data

[Paul Eggert]

Guy Harris wrote:

> The first suggestion is what I think Zefram was suggesting;
> the second suggestion sounds like what you're suggesting.

Yes, that sounds about right.

> Is that intended to reduce the number of zones to present
> to someone configuring the system if your system doesn't
> make a vigorous effort to support those times, and to
> reduce the effort needed to maintain them?

Yes to both.  The extra zones are a burden to users
and to maintainers, and for most users their cost exceeds
their benefit.

> Is it intended to be consistent with a rule forbidding
> adding *new* tzids due to differences in pre-1970
> standardized time?

Yes.  That rule's from "Theory".

> Is it intended to reduce political disputes over tzids -
> presumably by reducing the number of tzids and thus the
> number of possible points of complaint,

Yes, that's part of it.  But more important, it reduces
the number of zones put in only because a location is
politically "special" in some way.

> I went back through the archive and, if the controversial
> changes are the ones from the "Move links to 'backward' if
> they exist only because of country codes." message, I'm
> probably missing something, as that doesn't appear to be
> discarding existing pre-1970 splits, at least from the
> description.)

You're correct, those changes don't discard existing
pre-1970 splits.