Alexander Belopolsky added the comment: I think the timezone related problems are a red herring. Aware datetime +/- timedelta arithmetics is naive - tzinfo is ignored in calculations and copied to the result:
http://hg.python.org/cpython/file/c83ce2a1841c/Lib/datetime.py#l1711 The utcoffset only will only come into play if we want to implement time - time -> timedelta, but this problem is already there in time comparisons: http://hg.python.org/cpython/file/c83ce2a1841c/Lib/datetime.py#l1091 It is up to tzinfo subclass implementation writers to handle inability to compute utcoffset without date fields by raising an exception if necessary. It is perfectly fine for time - time to fail with an error coming from .utcoffset(). I also don't think the fate of #13936 has any bearing on this issue. As long as we are not trying to implement time + time -> time, we are not introducing any new notion of "zero time". ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue17267> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
