[tz] [PROPOSED] Merge timezones that are alike since 1970

[Paul Eggert]

On 5/29/21 7:18 AM, David Braverman via tz wrote:
> And why do we think users won't want to get accurate wall-clock time for times before Unix 0? Astronomy (and astrology) and historical research are just two (three) disciplines that need historical wall-clock time.

These users will continue to get sort-of-accurate time, which is all 
they're getting now. No serious astronomer etc. should expect accurate 
German wall-clock time from TZ='Europe/Berlin' for pre-1970 timestamps, 
and the same is true for Sweden, Kosovo, etc.

> Removing them is nothing more than an aesthetic decision, but one that will break thousands of applications, confuse users, and cause a public-relations nightmare for our merry band of volunteers.
We've been moving out-of-scope historical data to 'backzone' for years. 
It's worked just fine.