On 24 August 2015 at 14:05, Tim Peters <[email protected]> wrote: > [Tim] >> Oops! Somewhere around 2037-2038 it apparently lost all knowledge of >> US/Eastern daylight time. I expect this is why: >> >> >>> ez._utc_transition_times[-1] >> datetime.datetime(2037, 11, 1, 6, 0) >> >> That is, the last transition it knows about is the end of daylight time in >> 2037. > ... >> >> Digging deeper, I don't think I can pin this on tzfile. The docs say >> that, if possible, a tzfile also contains a POSIX-TZ-style rule to be >> used for times beyond the last explicit transition instant. In the >> US/Eastern tzfile shipped with this version of pytz, that's: >> >> EST5EDT,M3.2.0,M11.1.0 >> >> So a "complete" wrapping of zoneinfo also requires implementing such >> rules when present.
Yeah, I should really do that before 2037... > This appears to be the scoop, although I may be wrong about some: > when tzfile was first invented, like most other stuff at the time it > assumed the world would end before 2038 (the first year a signed > 32-bit int is too narrow to hold a UNIX(tm) seconds-since-1970 > timestamp). Values in a tzfile were all at most 4 bytes, zic > generated all transitions explicitly through the end of 2037, and that > was that. Not that the world would end. Just that we would be safely retired :) -- Stuart Bishop <[email protected]> http://www.stuartbishop.net/ _______________________________________________ Datetime-SIG mailing list [email protected] https://mail.python.org/mailman/listinfo/datetime-sig The PSF Code of Conduct applies to this mailing list: https://www.python.org/psf/codeofconduct/
