[Alexander Belopolsky] > >> As far as I understand, NodaTime to Python dictionary would have the > >> following translations: > >> > >> LocalDatetime: datetime with tzinfo=None (naive datetime) >
[Guido van Rossum] > > I have a slight concern here. In my own brain-universe there is a > difference > > between a *local* datetime and a *naive* datetime. A local datetime has > an > > implicit timezone (the one used by the system wall clock, or perhaps the > TZ > > env var). A naive datetime, as intended in the original design, has *no* > > timezone. > [Łukasz Rekucki] > If the timezone is implicit, then it's not kept together with the > object. Which means that the difference is purely in the behavior of > such object, e.g. converting to UTC: naive datetime requires passing a > timezone explicitly, while your local datetime just call > get_system_timezone() and uses that. I would say if you have both a > *naive* datetime and "*zoned* datetime, the use of this kind of > datetime with implicit timezone is rather limited because you can just > use a *zoned* variant with get_system_timezone() as its TZ > _explicitly_. > That's all fine, but my point remains, that the tz-less datetime object does *not* always mean local time. The definition I quoted from Alexander conflated the two, incorrectly IMO. [Guido] > > I also never meant the term "naive" to be used for the existing > arithmetic > > rules for tz-aware datetime objects -- I always meant "naive" to refer to > > tz-less datetime objects. I would prefer something like "classic > arithmetic" > > for tz-aware datetime objects. > > > > We can then introduce two new terms for different forms of arithmetic: > > "human arithmetic" for the form that can do things like "+ 2 months" in a > > way that (mostly) matches human expectations, and "strict arithmetic" for > > the form that Lennart needs (essentially move a specific number of > seconds > > along UTC). > > How about *time line* arithmetic ? It's also in Noda docs and avoids > discussing what is more "human". But "strict" sounds good too. > If that's what Noda uses, that's fine with me (the fewer vocabularies the better). > Is there some wiki-space where this could be put to so that people > don't have too search the archives? (I'm willing to do the work and > gather the info from this thread into it). Wikis are self-serve. Create one! -- --Guido van Rossum (python.org/~guido)
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