Python NonExistentTimeError
django, python, python-datetime
Solution
Django expects to work with timezone aware datetime objects.
From the Django documentation, the `now()` call would become:
import datetime
from django.utils.timezone import utc
now = datetime.datetime.utcnow().replace(tzinfo=utc)
expires = now + datetime.timedelta(hours=7)
Better still, use the `now()` function from `django.utils.timezone`.
Both `datetime.now()` and `datetime.utcnow()` return naive `datetime` objects which is not what Django requires. With a time zone applied to `expires`, Django is then able to convert back to UTC for storage as UTC in the database backend.
The `NonExistentTimeError` is actually thrown by code from the `pytz` module. The pytz documentation is definitely worth reading as there's many gotchas when dealing with time zones.
Problem
I'm creating a simple Django API where access tokens are used. The idea is that, when a user requests a token, said token is valid for the next 7 hours. However when generating the token I obtain a Python NonExistentTimeError. Code is: ``` #Django view ... expires = datetime.datetime.now() + datetime.timedelta(hours=7) token = APIMasterToken.objects.create( token=token, expiration_date=expires ) ``` However I obtain an exception generating a token with said date: ``` NonExistentTimeError at /api/obtain_master_token/ 2013-03-10 02:05:12.179508 ``` What does this error mean and how can I solve it? EDIT: I just read the documentation and it would appear this error is raised when a day occurs that has a clock change following DST. However, I don't know how to solve the problem. Shouldn't the timedelta function take care of this?