[Datetime-SIG] Adding PEP 495 support to dateutil

[Tim Peters]

[Paul Ganssle <paul at ganssle.io>]
> Appreciate the advice, I have to admit that these edge cases seem rare
> enough that they haven't been a priority for me

On a third look, I think you can ignore my rant about the gmt/std/wall
indicators:  those don't appear to be _used_ at all in the current
dateutil code.  I was either hallucinating, or (mis)remembering some
older version of the code.  But since they're not used, you could save
some memory space & cycles by not bothering to read them from the
tzfile to begin with.

About edge cases, as before it's simply not possible to get them all
right today, nor to get as many right as _is_ possible for IANA zones
today without overriding .fromutc().  If I were you I'd wait to see
PEP 495's fate.  Then "always right all the time" could become
possible.


> (I'm still trying to wrap up a release that doesn't occasionally break the
> parser for certain strings on the 29th-31st of every month, for example).

Just fix the 30th, and call it progress ;-)