Timezone.now() vs datetime.datetime.now()

Question

When should I be using django's timezone.now() and when should I be using python's datetime.datetime.now().

For example, in the following INSERT which would make more sense?

- Product.objects.create(title='Soap', date_added=datetime.datetime.now())
- Product.objects.create(title='Soap', date_added=timezone.now())

Is there a rule of thumb on when to use each?

[Is link this useful?](http://stackoverflow.com/questions/10783864/django-1-4-timezone-now-vs-datetime-datetime-now) — helloV, Nov 15 '14 at 19:52
Does this answer your question? [django 1.4 timezone.now() vs datetime.datetime.now()](https://stackoverflow.com/questions/10783864/django-1-4-timezone-now-vs-datetime-datetime-now) — ggorlen, Nov 17 '21 at 17:41

score 43 · Accepted Answer · edited Jan 11 '20 at 18:36

43

Just always use timezone.now(). Django now has timezone support which requires timezone 'aware' datetime objects. datetime.now() will return a timezone naive object, whereas timezone.now() will return a timezone aware object.

Read more about Django timezones

edited Jan 11 '20 at 18:36

culix

10,188
6
36
52

answered Nov 15 '14 at 19:55

dgel

16,352
8
58
75

12

More precisely, `timezone.now()` will return a naive or aware `datetime` based on the `USE_TZ` setting. – Kevin Christopher Henry Nov 16 '14 at 05:19
Could you point me to a resource where I could get to know more about each? – Shubham Aggarwal Mar 29 '16 at 19:26
3

Sure: https://docs.djangoproject.com/en/1.9/topics/i18n/timezones/#naive-and-aware-datetime-objects – dgel Mar 30 '16 at 01:53
1

That django 1.9 link is broken, so I added a link to the current stable docs – culix Jan 11 '20 at 18:36

score 4 · Answer 2 · answered Oct 09 '19 at 14:02

4

You can write in shell, for example:

timezone.datetime.now() < timezone.now()

And the error message is:

TypeError: can't compare offset-naive and offset-aware datetimes

They are different objects, only timezone.now() have UTC support

answered Oct 09 '19 at 14:02

eEmanuel Oviedo

49
4

Can you elaborate on what UTC support means? – Ren Dec 25 '19 at 16:59
1

From Django Documentation: Python’s datetime.datetime objects have a tzinfo attribute that can be used to store time zone information, represented as an instance of a subclass of datetime.tzinfo. When this attribute is set and describes an offset, a datetime object is aware. Otherwise, it’s naive. – eEmanuel Oviedo Jan 08 '20 at 12:20
1

"only timezone.now() have UTC support" means "only timezone.now() have tzinfo attribute" – eEmanuel Oviedo Jan 08 '20 at 12:22

score 2 · Answer 3 · answered Jan 11 '20 at 18:35

2

If you want to use UTC, and you're using Python 3.2 or higher, this answer says you can do:

import datetime
datetime.datetime.now(datetime.timezone.utc)

This will give you a timezone-aware UTC datetime.

answered Jan 11 '20 at 18:35

culix

10,188
6
36
52

Timezone.now() vs datetime.datetime.now()

3 Answers3

Linked