[tz] Converting cities to tz identifiers (tangent)

[Garrett Wollman]

<<On Tue, 20 Feb 2018 16:36:55 -0500, John Hawkinson <jhawk at MIT.EDU> said:

> Paul.Koning at dell.com <Paul.Koning at dell.com> wrote on Tue, 20 Feb 2018
> at 20:10:33 +0000 in <4FEED0AD-A1BA-4D23-B461-CB07F0F85045 at dell.com>:

>> I would not recommend that.  "backward" exists, as the name
>> suggests, only for backward compatibility with old naming
>> conventions.

> I'm not sure we've made such a statement of deprecation. I think a
> lot of people use the US/* style, even though it's not what the tz
> db prefers. I think a lot of people would be up-in-arms if those
> identifiers were deprecated anytime in foreseeable life of the
> project (measured in decades). But perhaps I am wrong (or too
> conservative).

When I was the timezone maintainer for FreeBSD, I made a deliberate
decision not to use the backward file (unless the user rebuilt their
system after changing a make variable).  I believe the current
maintainer has continued this policy, so there's at least one
downstream platform that does not support the old names and has not
done so for about two decades.  The zone.tab file (which FreeBSD's
timezone chooser uses) does not reference the "backward" zones as I
recall.

-GAWollman