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

This error means you are comparing a timezone-aware datetime with a naive datetime that has no timezone info. Fix it by consistently using django.utils.timezone.now() instead of datetime.datetime.now(), enabling USE_TZ = True in settings, and using timezone.make_aware() to convert any naive datetimes before comparison.

Reading the Stack Trace

Here's what each line means:

• File "/app/subscriptions/views.py", line 19, in check_expiry: The view compares subscription.expires_at (timezone-aware from the database) with datetime.now() (naive, no timezone info).
• if subscription.expires_at < datetime.datetime.now():: datetime.datetime.now() returns a naive datetime. When USE_TZ is True, DateTimeField values from the database are timezone-aware.
• TypeError: can't compare offset-naive and offset-aware datetimes: Python refuses to compare datetimes with and without timezone information because the comparison would be ambiguous.

Common Causes

import datetime

def check_expiry(request, subscription_id):
    subscription = Subscription.objects.get(id=subscription_id)
    if subscription.expires_at < datetime.datetime.now():  # Naive datetime
        return JsonResponse({'status': 'expired'})

from datetime import datetime, timedelta

# Naive datetime in a queryset filter
recent = Event.objects.filter(
    created_at__gte=datetime.now() - timedelta(hours=24)
)

from datetime import datetime

def sync_events(api_response):
    for event in api_response['events']:
        event_time = datetime.strptime(event['time'], '%Y-%m-%d %H:%M:%S')  # Naive
        if event_time > Event.objects.latest('created_at').created_at:  # Aware
            Event.objects.create(name=event['name'], created_at=event_time)

The Fix

Replace datetime.datetime.now() with django.utils.timezone.now(), which returns a timezone-aware datetime consistent with Django's USE_TZ setting. For naive datetimes from external sources, use timezone.make_aware() to add timezone information.

import datetime

def check_expiry(request, subscription_id):
    subscription = Subscription.objects.get(id=subscription_id)
    if subscription.expires_at < datetime.datetime.now():
        return JsonResponse({'status': 'expired'})
    return JsonResponse({'status': 'active'})

from django.utils import timezone

def check_expiry(request, subscription_id):
    subscription = Subscription.objects.get(id=subscription_id)
    if subscription.expires_at < timezone.now():
        return JsonResponse({'status': 'expired'})
    return JsonResponse({'status': 'active'})

# For external naive datetimes, make them aware:
# from django.utils import timezone
# aware_dt = timezone.make_aware(naive_dt, timezone.utc)

Testing the Fix

import pytest
from datetime import timedelta
from django.test import TestCase, Client
from django.utils import timezone
from subscriptions.models import Subscription


class TestExpiryCheck(TestCase):
    def setUp(self):
        self.client = Client()

    def test_expired_subscription(self):
        sub = Subscription.objects.create(
            expires_at=timezone.now() - timedelta(days=1)
        )
        response = self.client.get(f'/subscriptions/{sub.id}/check/')
        assert response.json()['status'] == 'expired'

    def test_active_subscription(self):
        sub = Subscription.objects.create(
            expires_at=timezone.now() + timedelta(days=30)
        )
        response = self.client.get(f'/subscriptions/{sub.id}/check/')
        assert response.json()['status'] == 'active'

    def test_no_timezone_comparison_error(self):
        sub = Subscription.objects.create(
            expires_at=timezone.now() + timedelta(days=1)
        )
        # Should not raise TypeError
        response = self.client.get(f'/subscriptions/{sub.id}/check/')
        assert response.status_code == 200

Run your tests:

pytest

Pushing Through CI/CD

git checkout -b fix/timezone-naive-comparison,git add subscriptions/views.py,git commit -m "fix: use timezone.now() instead of datetime.now() for aware comparison",git push origin fix/timezone-naive-comparison

Your CI config should look something like this:

name: CI
on:
  pull_request:
    branches: [main]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: '3.11'
          cache: 'pip'
      - run: pip install -r requirements.txt
      - run: pytest --tb=short -q

The Full Manual Process: 18 Steps

Here's every step you just went through to fix this one bug:

1. Notice the error alert or see it in your monitoring tool
2. Open the error dashboard and read the stack trace
3. Identify the file and line number from the stack trace
4. Open your IDE and navigate to the file
5. Read the surrounding code to understand context
6. Reproduce the error locally
7. Identify the root cause
8. Write the fix
9. Run the test suite locally
10. Fix any failing tests
11. Write new tests covering the edge case
12. Run the full test suite again
13. Create a new git branch
14. Commit and push your changes
15. Open a pull request
16. Wait for code review
17. Merge and deploy to production
18. Monitor production to confirm the error is resolved

Total time: 30-60 minutes. For one bug.

pip install bugstack

import bugstack

bugstack.init(api_key=os.environ["BUGSTACK_API_KEY"])

Deploying the Fix (Manual Path)

1. Run the full test suite locally to confirm timezone comparisons work.
2. Open a pull request with the timezone fix.
3. Wait for CI checks to pass on the PR.
4. Have a teammate review and approve the PR.
5. Merge to main and verify datetime logic in staging.

Frequently Asked Questions