[tz] Issues with pre-1970 information in TZDB

Paul Eggert eggert at cs.ucla.edu
Fri Sep 24 00:35:42 UTC 2021

On 9/23/21 11:28, Brooks Harris wrote:

> It seems these time zones could not be changed or merged to backzone. So 
> what constitutes "pre-1970" and justifies a move to backzone?

This is documented in the guidelines for timezone identifiers:


Look for "1970" on that page.

  I gather
> this 'merge' procedure began in 2015? Is there documentation or 
> discussion of that decision?

I think it was more like 2013 but do not recall the details. Discussions 
are archived here:


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