Okay. Thanks for the clarity. And app developers also want more locations that have differences before 1970. 'Further-back data', which implies zones which are not relevant to o/s work. But the further you go back the more zones this implies, until we are all back to local solar time. So assuming we could add those somewhere, with so many potential zones how would one identify them... which is where I propose current ISO country/city ids for the backfiles, as a way of making them more accessible and also as a way of deferring political debate off this list and to ISO instead. I now have no problem with the effort to merge zones in the main table, and app developers with historical needs would focus more on using and improving the back files, potentially adding new pre-1970 zones only to the backfiles at some point. These extra zones could be ignored by zic, but I don't use zic, so I cannot really comment on that. On 2021-06-01 22:42, Guy Harris wrote:
OSes definitely use past tz data: