[Datetime-SIG] What's are the issues?

[Chris Barker]

On Tue, Jul 28, 2015 at 2:38 PM, Felipe Ochoa <felipe.nospam.ochoa at gmail.com
> wrote:

> Here is my best shot at categorizing the different outstanding design
> issues:
>

great, thanks!

My thoughts:
(some obvious)

NOTE: I'm assuming that timedelta is the same as it is now -- i.e. "naive",
or simply representing a timespan nothing t do with calendars.

1. Datetime arithmetic
>     a) datetime +/- timedelta
>         i. Naive (no tzinfo) datetime objects
>

same as now


>         ii. Aware (with tzinfo) datetime objects
>

If the math is done in UTC, then there is no issue, yes? the timedelta is
added or subtracted, and the result has the same tzinfo object.


>     b) datetime - datetime
>         i. When both are naive
>
same as now.

>         ii. When both have same tzinfo
>

Just do the math. Store as UTC makes it easy. return a timedelta.


>         iii. When the two have different tzinfos
>

Do the math in UTC, return a timedelta.


> 2. Inter-timezone conversion
>     a) adding an isdst (or which) attribute
>
yup -- and I've bike-shedeed enough without getting into what to call it!

>     b) algorithm specification
>

what part of the algorithm? seems pretty straightforward to me (the
algorithm, anyway)

So really a lot of bike-shedding on pyton-dev ;-)

-CHB

-- 

Christopher Barker, Ph.D.
Oceanographer

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