[Numpy-discussion] Dates and times and Datetime64 (again)

[Nathaniel Smith]

On 28 Mar 2014 05:00, "Sankarshan Mudkavi" <smudkavi at uwaterloo.ca> wrote:
>
> Hi all,
>
> Apologies for the delay in following up, here is an expanded version of
the proposal, which hopefully clears up most of the details. I have not
included specific implementation details for the code, such as which
functions to modify etc. since I think those are not traditionally included
in NEPs?

The format seems fine to me. Really the point is just to have a document
that we can use as reference when deciding on behaviour, and this does that
:-).

Three quick comments:

1- You give as an example of "naive" datetime handling:

>>> np.datetime64('2005-02-25T03:00Z')
np.datetime64('2005-02-25T03:00')

This IIUC is incorrect. The Z modifier is a timezone offset, and for normal
"naive" datetimes would cause an error.

2- It would be good to include explicitly examples of conversion to and
from datetimes alongside the examples of conversions to and from strings.

3- It would be good to (eventually) include some discussion of the impact
of the preferred proposal on existing code. E.g., will this break a lot of
people's pipelines? (Are people currently *always* adding timezones to
their numpy input to avoid the problem, and now will have to switch to the
opposite behaviour depending on numpy version?) And we'll want to make sure
to get feedback from the pydata@ (pandas) list explicitly, though that can
wait until people here have had a chance to respond to the first draft.

Thanks for pushing this forward!
-n
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