Can't compare naive and aware <= challenge.datetime_end

I am trying to compare the current date and time with dates and times specified in models using comparison operators:

if challenge.datetime_start <= <= challenge.datetime_end:

The script errors out with:

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

The models look like this:

class Fundraising_Challenge(models.Model):
    name = models.CharField(max_length=100)
    datetime_start = models.DateTimeField()
    datetime_end = models.DateTimeField()

I also have django using locale date and times.

What I haven't been able to find is the format django uses for DateTimeField(). Is it naive or aware? And how do I get to recognize locale datetime?

Asked By: sccrthlt

Answer #1:

By default, the datetime object is naive in Python, so you need to make both of them either naive or aware datetime objects. This can be done using:

import datetime
import pytz


challenge.datetime_start = utc.localize(challenge.datetime_start) 
challenge.datetime_end = utc.localize(challenge.datetime_end) 
# now both the datetime objects are aware, and you can compare them

Note: This would raise a ValueError if tzinfo is already set. If you are not sure about that, just use

start_time = challenge.datetime_start.replace(tzinfo=utc)
end_time = challenge.datetime_end.replace(tzinfo=utc)

BTW, you could format a UNIX timestamp in datetime.datetime object with timezone info as following

d = datetime.datetime.utcfromtimestamp(int(unix_timestamp))
d_with_tz = datetime.datetime(
Answered By: Viren Rajput

Answer #2: is not timezone aware.

Django comes with a helper for this, which requires pytz

from django.utils import timezone
now =

You should be able to compare now to challenge.datetime_start

Answered By: Alfredo Aguirre

Answer #3:

One line of code solution

if timezone_aware_var <=
    pass #some code

Explained version

# Timezone info of your timezone aware variable
timezone = your_timezone_aware_variable.tzinfo

# Current datetime for the timezone of your variable
now_in_timezone =

# Now you can do a fair comparison, both datetime variables have the same time zone
if your_timezone_aware_variable <= now_in_timezone:
    pass #some code


You must add the timezone info to your now() datetime.
However, you must add the same timezone of the reference variable; that is why I first read the tzinfo attribute.

Answered By: ePi272314

Answer #4:

Disable time zone. Use challenge.datetime_start.replace(tzinfo=None);

You can also use replace(tzinfo=None) for other datetime.

if challenge.datetime_start.replace(tzinfo=None) <= <= challenge.datetime_end.replace(tzinfo=None):
Answered By: Amin Fathi

Answer #5:

So the way I would solve this problem is to make sure the two datetimes are in the right timezone.

I can see that you are using which will return the systems current time, with no tzinfo set.

tzinfo is the information attached to a datetime to let it know what timezone it is in. If you are using naive datetime you need to be consistent through out your system. I would highly recommend only using datetime.utcnow()

seeing as somewhere your are creating datetime that have tzinfo associated with them, what you need to do is make sure those are localized (has tzinfo associated) to the correct timezone.

Take a look at Delorean, it makes dealing with this sort of thing much easier.

Answered By: myusuf3

Answer #6:

It is working form me. Here I am geeting the table created datetime and adding 10 minutes on the datetime. later depending on the current time, Expiry Operations are done.

from datetime import datetime, time, timedelta
import pytz

Added 10 minutes on database datetime

table_datetime = '2019-06-13 07:49:02.832969' (example)

# Added 10 minutes on database datetime
# table_datetime = '2019-06-13 07:49:02.832969' (example)

table_expire_datetime = table_datetime + timedelta(minutes=10 )

# Current datetime
current_datetime =

# replace the timezone in both time
expired_on = table_expire_datetime.replace(tzinfo=utc)
checked_on = current_datetime.replace(tzinfo=utc)

if expired_on < checked_on:
    print("Time Crossed)
    print("Time not crossed ")

It worked for me.

Answered By: Chandan Sharma

Answer #7:

You are trying to set the timezone for date_time which already has a timezone. Use replace and astimezone functions.

local_tz = pytz.timezone('Asia/Kolkata')

current_time =
Answered By: Vitthal Sarode

Answer #8:


dt = datetimeObject.strftime(format) # format = your datetime format ex) '%Y %d %m'
dt = datetime.datetime.strptime(dt,format)

So do this:

start_time = challenge.datetime_start.strftime('%Y %d %m %H %M %S')
start_time = datetime.datetime.strptime(start_time,'%Y %d %m %H %M %S')

end_time = challenge.datetime_end.strftime('%Y %d %m %H %M %S')
end_time = datetime.datetime.strptime(end_time,'%Y %d %m %H %M %S')

and then use start_time and end_time

Answered By: Harispy
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