Resolving AmbiguousTimeError from Django's make_aware
Prophylactics
You should avoid naive datetimes in the first place using the following:
from django.utils import timezone
now = timezone.now()
If like me, you have naive times already that you must convert, read on!
Django 1.9+:
You can resolve the AmbiguousTimeError by using the following (thanks to GeyseR):
make_aware(some_datetime, get_current_timezone(), is_dst=False)
Django 1.x - 1.8:
The problem is that make_aware just calls timezone.localize, passing None to the argument is_dst:
timezone.localize(value, is_dst=None)
The argument is_dst is specifically what is used to resolve this ambiguous time error (http://pytz.sourceforge.net/#tzinfo-api).
The solution is to call timezone.localize yourself:
get_current_timezone().localize(some_datetime, is_dst=False)
Having is_dst=False sets it to the first of the two possible times. is_dst=True would be the second.
Since django 1.9 make_aware utility function has is_dst
parameter.
So you can use it for solving AmbiguousTimeError exception:
from django.utils.timezone import get_current_timezone, make_aware
make_aware(some_datetime, get_current_timezone(), is_dst=True)
or
make_aware(some_datetime, get_current_timezone(), is_dst=False)
Related section in django docs
For people searching on this error:
In your Django code, replace:
today = datetime.datetime.today()
with
from django.utils import timezone
today = timezone.now()