[Python-Dev] Status on PEP-431 Timezones (original) (raw)

Lennart Regebro regebro at gmail.com
Wed Apr 15 17:00:47 CEST 2015

OK, so I just had a realization.

Because we want some internal flag to tell if the datetime is in DST or not, the datetime pickle format will change. And the datetime pickle format changing is the biggest reason I had against changing the internal representation to UTC.

So because of this, perhaps we actually should change the internal representation to UTC, because that makes the issues I'm fighting with now so much simpler. (I'm currently trying to get arithmetic to do the right thing in all cases, which is crazy complicated).

We can add support to unpickle previous datetimes, but we won't be able to add forwards compatibility, meaning that pickles saved in Python 3.5 will not be unpicklable in Python 3.4.

Please discuss.

//Lennart

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