Django: can't subtract offset-naive and offset-aware datetimes

Question

i have a 'free_trial' function in my app that allows users who have an account not older than 7 days to try my app.

user model

from datetime import datetime, timedelta

    class CustomUser(AbstractUser):
    
        def free_trial(self):
            if (self.date_joined - datetime.now()) < timedelta(days=7):
                return True

templates

{% if user.free_trial %}

#Access Features

{% endif %}

but i'm getting this error on template can't subtract offset-naive and offset-aware datetimes

score 2 · Accepted Answer · answered Apr 12 '21 at 17:28

2

Just use timezone aware time for your calculation:

from django.utils.timezone import localdate

class CustomUser(AbstractUser):

    def free_trial(self):
        if (self.date_joined - localdate()) < timedelta(days=7):
            return True

answered Apr 12 '21 at 17:28

ruddra

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score 0 · Answer 2 · answered Apr 12 '21 at 17:05

One of those datetimes is in a particular time zone ("offset-aware"), and the other is not in any particular timezone ("offset-naïve"), see this part of the Python manual and this previous SO question. They can't be sensibly compared — you either need to add timezone information to one, remove timezone information from the other, or use a seconds-since-the-epoch representation for both. Which one you want to do depends on how you want your application to behave.

Django: can't subtract offset-naive and offset-aware datetimes

2 Answers2