DJANGO_CELERY_BEAT_TZ_AWARE = False Time zone usage issue #924
Description
I checked the solutions in celery/django-celery-beat/issues/798, specifically #798 (comment).
However, this still doesn't solve the problem.
Core Problem Statement
The root cause occurs when USE_TZ ≠ DJANGO_CELERY_BEAT_TZ_AWARE
This mismatch creates timezone awareness incompatibility between
leading to TypeError: can't compare offset-naive and offset-aware datetimes during time comparisons.
Key Conflict Points
Django's USE_TZ Behavior
| Setting | Storage Behavior | Read Behavior |
|---|---|---|
USE_TZ=True |
Stores all times as UTC | Converts to UTC timezone when reading |
USE_TZ=False |
Stores timezone-naive times | Reads timezone-naive times |
Celery Beat's DJANGO_CELERY_BEAT_TZ_AWARE Behavior
| Setting | Time Generation Method |
|---|---|
True |
datetime.now(self.app.timezone) (timezone-aware) |
False |
datetime.utcnow() (timezone-naive UTC) |
def _default_now(self):
if getattr(settings, 'DJANGO_CELERY_BEAT_TZ_AWARE', True):
now = datetime.datetime.now(self.app.timezone)
else:
# this ends up getting passed to maybe_make_aware, which expects
# all naive datetime objects to be in utc time.
now = datetime.datetime.utcnow()
return nowConflict Scenarios Analysis
| Scenario | DJANGO_CELERY_BEAT_TZ_AWARE | USE_TZ | _default_now() Returns | ORM Returns | Result |
|---|---|---|---|---|---|
| 1 | True | False | Timezone-aware | Timezone-naive | Comparison error |
| 2 | False | True | Timezone-naive | Timezone-aware | Comparison error |
| 3 | True | True | Timezone-aware | Timezone-aware | Valid |
| 4 | False | False | Timezone-naive | Timezone-naive | Valid |
Core Problems with last_run_at
When USE_TZ ≠ DJANGO_CELERY_BEAT_TZ_AWARE:
Celery Version: 5.5.1
Celery-Beat Version: 2.8.1