Using strftime on a django datetime produces a UTC time in the string

Question

I have the following code in one of my models:

def shortDescription(self):
    return self.name + ' ' + self.class_date.strftime("%I:%M")

self.class_date is a timezone aware DateTimeField, self.class_date.is_aware() is True, USE_TZ is True.

The shortDescription returns a string that gives the time in UTC rather than the default timezone, putting {{ aclass.class_date }} in the template displays the time in the correct zone.

Is strftime always working on the base, native time? Or what else is going on here?

What do you mean by "timezone aware date"? What class is it? — David Robinson, Aug 10 '12 at 20:54

score 52 · Accepted Answer · answered Aug 10 '12 at 21:09

52

When you directly reference pieces of the datetime like %I or %M, it uses it straight as it is with no locale conversion. If you included %Z you'd see that the time is in UTC. If you want locale-aware results, you need use the more limited %X, which will simply spit out the full time converted for the locale.

If you need more, you'll have to convert it:

from django.utils import timezone

def shortDescription(self):
    class_date = timezone.localtime(self.class_date)
    return self.name + ' ' + class_date.strftime("%I:%M")

Or, you can rely on the date filter, which automatically does this for you:

from django.template import defaultfilters

def shortDescription(self):
    return self.name + ' ' + defaultfilters.date(self.class_date, 'g:i')

answered Aug 10 '12 at 21:09

Chris Pratt

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Excellent. And I didn't know about the defaultfilters trick at all. – Rob Osborne Aug 10 '12 at 23:20
1

Yeah, I use it all the time. Django template filters are just regular methods, so you can use any of them anywhere in your code. `defaultfilters.slugify` comes in handy quite often as well. – Chris Pratt Aug 13 '12 at 14:31
Does not work for me, [same Problem here](https://stackoverflow.com/questions/22050530/django-defaultfilters-date-not-timezone-aware) – Timo Mar 07 '18 at 07:24
The first approach worked better. Thank you for the solution. :) – Eerik Sven Puudist Apr 28 '19 at 17:57
2

`class_date` needs to be converted to local time in the second approach too. – rowman Aug 07 '19 at 14:57

Using strftime on a django datetime produces a UTC time in the string

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