RuntimeWarning: DateTimeField received a naive datetime

Question

I m trying to send a simple mail using IPython. I have not set up any models still getting this error. What can be done?

Error : /home/sourabh/Django/learn/local/lib/python2.7/site-packages/django/db/models/fields/init.py:827: RuntimeWarning: DateTimeField received a naive datetime (2013-09-04 14:14:13.698105) while time zone support is active. RuntimeWarning)

Tried : The first step is to add USE_TZ = True to your settings file and install pytz (if possible).

Error changed:

(learn)sourabh@sL:~/Django/learn/event$ python manage.py shell
/home/sourabh/Django/learn/local/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py:53: RuntimeWarning: SQLite received a naive datetime (2013-09-05 00:59:32.181872) while time zone support is active.
  RuntimeWarning)

Theologize

Answer 1

The problem is not in Django settings, but in the date passed to the model. Here's how a timezone-aware object looks like:

>>> from django.utils import timezone
>>> import pytz
>>> timezone.now()
datetime.datetime(2013, 11, 20, 20, 8, 7, 127325, tzinfo=pytz.UTC)

And here's a naive object:

>>> from datetime import datetime
>>> datetime.now()
datetime.datetime(2013, 11, 20, 20, 9, 26, 423063)

So if you are passing email date anywhere (and it eventually gets to some model), just use Django's now(). If not, then it's probably an issue with an existing package that fetches date without timezone and you can patch the package, ignore the warning or set USE_TZ to False.

Altorilievo

Where you write tzinfo=<UTC>, what is <UTC>? That is not a syntactic construct I have seen. – Treenatreenail

A bit late to the party, but what you are seeing is output from the shell. More specifically, it's the output from the datetime object's repr method, that returns printable information of the object. – Tricorn

In places where you were using datetime.now, change it to timezone.now, and add from django.utils import timezone at the top. – Mosqueda

For those still looking for that <UTC> part, you can use this: import pytz datetime.datetime(2013, 11, 20, 20, 8, 7, 127325, tzinfo=pytz.UTC) – Jephum

My settings are USE_TZ = True, TIME_ZONE = 'UTC'. But when I use timezone.now() it doesn't show tzinfo=<UTC>.... So this datetime object is passed as naive one. Why does it happen? – Potshot

In [3]: timezone.datetime.strptime("2017-01-01 23:11:11", '%Y-%m-%d %H:%M:%S') Out[3]: datetime.datetime(2017, 1, 1, 23, 11, 11) – Potshot

Hi, I'm trying to parse datetime string from frontend simillar to @Potshot using timezone.datetime.strptime. the result is correct as expected, but I stil got naive object warning. – Brandes

@Jephum the Django docs seem to suggest that doing that is not recommended? docs.djangoproject.com/en/dev/topics/i18n/timezones/… – Fredette

Answer 2

Use django.utils.timezone.make_aware function to make your naive datetime objects timezone aware and avoid those warnings.

It converts naive datetime object (without timezone info) to the one that has timezone info (using timezone specified in your django settings if you don't specify it explicitly as a second argument):

import datetime
from django.conf import settings
from django.utils.timezone import make_aware

naive_datetime = datetime.datetime.now()
naive_datetime.tzinfo  # None

settings.TIME_ZONE  # 'UTC'
aware_datetime = make_aware(naive_datetime)
aware_datetime.tzinfo  # <UTC>

Wastage

Thanks for this answer, it's the most django-compliant way to transform naive dates into dates with the timezone of my django settings :) – Neutralization

Is it possible to put this in models.py? – Armlet

@Armlet there is no need to change anything in models if you use utc timezone by default, auto_now and auto_now_add will work fine for datetime fields. If you need to have timezone aware current datetime object in models for some reason - use django.utils.timezone.now() function. – Wastage

What if one is using it in models like ` created = models.DateTimeField(default=datetime.now)` ? How should it be done here? – Mussman

Answer 3

Just to fix the error to set current time

from django.utils import timezone
import datetime

datetime.datetime.now(tz=timezone.utc) # you can use this value

Fundamentalism

and for datetime.datetime(9999, 01, 01, tzinfo=timezone.utc) – Jeraldjeraldine

IMO this is the most practical solution – Arenaceous

from django.utils import timezone timezone.now() #will also work – Caye

Answer 4

Quick and dirty - Turn it off:

USE_TZ = False

in your settings.py

Leonelleonelle

When USE_TZ is True and the database supports time zones (e.g. PostgreSQL), it is an error to set this option docs.djangoproject.com/en/2.2/ref/settings/#time-zone – Glaciate

Answer 5

make sure settings.py has USE_TZ = True

In your python file:

from django.utils import timezone

timezone.now() # use its value in model field

Caye

Answer 6

One can both fix the warning and use the timezone specified in settings.py, which might be different from UTC.

For example in my settings.py I have:

USE_TZ = True
TIME_ZONE = 'Europe/Paris'

Here is a solution; the advantage is that str(mydate) gives the correct time:

>>> from datetime import datetime
>>> from django.utils.timezone import get_current_timezone
>>> mydate = datetime.now(tz=get_current_timezone())
>>> mydate
datetime.datetime(2019, 3, 10, 11, 16, 9, 184106, 
    tzinfo=<DstTzInfo 'Europe/Paris' CET+1:00:00 STD>)
>>> str(mydate)
'2019-03-10 11:16:09.184106+01:00'

Another equivalent method is using make_aware, see dmrz post.

Verisimilitude

i just followed your idea above and used an effective timezone string in my test.py. It worked flawless and i feel is even better than modifying setting.py just for this purpose. – Topmast

Answer 7

If you are trying to transform a naive datetime into a datetime with timezone in django, here is my solution:

>>> import datetime
>>> from django.utils import timezone
>>> t1 = datetime.datetime.strptime("2019-07-16 22:24:00", "%Y-%m-%d %H:%M:%S")
>>> t1
    datetime.datetime(2019, 7, 16, 22, 24)
>>> current_tz = timezone.get_current_timezone()
>>> t2 = current_tz.localize(t1)
>>> t2
    datetime.datetime(2019, 7, 16, 22, 24, tzinfo=<DstTzInfo 'Asia/Shanghai' CST+8:00:00 STD>)
>>>

t1 is a naive datetime and t2 is a datetime with timezone in django's settings.

Railey

Answer 8

You can also override settings, particularly useful in tests:

from django.test import override_settings

with override_settings(USE_TZ=False):
    # Insert your code that causes the warning here
    pass

This will prevent you from seeing the warning, at the same time anything in your code that requires a timezone aware datetime may give you problems. If this is the case, see kravietz answer.

Pampa

Answer 9

In the model, do not pass the value:

timezone.now()

Rather, remove the parenthesis, and pass:

timezone.now

If you continue to get a runtime error warning, consider changing the model field from DateTimeField to DateField.

Surplus

Answer 10

I use function to covert date -> datetime aware format like this:

from datetime import datetime, date
from django.utils import timezone

def date_to_datetime_aware(d:date) -> datetime:
    dt = datetime.combine(d, datetime.min.time())
    dt_aware = timezone.make_aware(dt)
    return dt_aware

It helps me to awoid Django RuntimeWarning.

Luculent

Answer 11

I encountered this warning when using the following model.

from datetime import datetime

class MyObject(models.Model):
    my_date = models.DateTimeField(default=datetime.now)

To fix it, I switched to the following default.

from django.utils import timezone

class MyObject(models.Model):
    my_date = models.DateTimeField(default=timezone.now)

Evangelista

type object 'datetime.timezone' has no attribute 'now' – Mcdavid

Type object datetime.timezone has not indeed, but my solution is referring to django.utils.timezone which has the now attribute. – Evangelista

Answer 12

If you need to convert the actual date string to date object, I have got rid of the warning by simply using astimezone:

>>> from datetime import datetime, timezone
>>> datetime_str = '2013-09-04 14:14:13.698105'
>>> datetime_object = datetime.strptime(datetime_str, "%Y-%m-%d %H:%M:%S.%f")
>>> datetime_object.astimezone(timezone.utc)
datetime.datetime(2013, 9, 4, 6, 14, 13, 698105, tzinfo=datetime.timezone.utc)

Beaty