On Mon, Aug 31, 2015 at 8:16 PM, Alexander Belopolsky < alexander.belopolsky@gmail.com> wrote:

Sorry, but PEP 495 has never promised you that: "instances that differ only by the value of fold will compare as equal. Applications that need to differentiate between such instances should check the value of fold or convert them to a timezone that does not have ambiguous times."

When I was writing some early drafts, I thought about advising users to use (local_datetime, local_datetime.fold) pairs as dictionary keys, but decided not to because using local_datetime.astimezone(timezone.utc) is a much better option. Now I think such advise may be relevant if a user truly has a need to sort out timestamps that come from many different timezones and for some reason wants to avoid conversion to UTC, but I don't think it will belong to the PEP.