On Jun 27, 2023, at 12:19 AM, Magnus Fromreide via tz <tz@iana.org> wrote:
My personal opinion is that the default IANA build should say nothing about dates before 1970-01-01 - it should, in particular, not claim that changes for some random place (like Berlin) applies to some other place (like Copenhagen).
And, presumably, it shouldn't make any other claims about Copenhagen before 1970-01-0, either. Or about Berlin, or about New York City, or any of the other cities chosen for tzdb region names, for that matter. (Not that Continent/City should be read as only making claims about that city.) (At this point, I wish we could get away with doing as Microsoft do, and just return -1 for all attempts to call localtime() for dates prior to the UNIX Epoch.)