Make tz naive and tz aware be configurable (#203)

Add readme

Add test settings

Add settings import

README.rst

@@ -229,6 +229,13 @@ pip command::
 
     $ pip install https://github.com/celery/django-celery-beat/zipball/master#egg=django-celery-beat
 
+
+TZ Awareness:
+-------------
+
+If you have a project that is time zone naive, you can set `DJANGO_CELERY_BEAT_TZ_AWARE=False` in your settings file.
+
+
 .. |build-status| image:: https://secure.travis-ci.org/celery/django-celery-beat.svg?branch=master
     :alt: Build status
     :target: https://travis-ci.org/celery/django-celery-beat

django_celery_beat/models.py

@@ -6,6 +6,7 @@
 import timezone_field
 from celery import schedules
 from celery.five import python_2_unicode_compatible
+from django.conf import settings
 from django.core.exceptions import MultipleObjectsReturned, ValidationError
 from django.core.validators import MaxValueValidator
 from django.db import models
@@ -192,13 +193,23 @@ def __str__(self):
 
     @property
     def schedule(self):
-        return TzAwareCrontab(
+        crontab = schedules.crontab(
             minute=self.minute,
-            hour=self.hour, day_of_week=self.day_of_week,
+            hour=self.hour,
+            day_of_week=self.day_of_week,
             day_of_month=self.day_of_month,
             month_of_year=self.month_of_year,
-            tz=self.timezone
         )
+        if settings.DJANGO_CELERY_BEAT_TZ_AWARE:
+            crontab = TzAwareCrontab(
+                minute=self.minute,
+                hour=self.hour,
+                day_of_week=self.day_of_week,
+                day_of_month=self.day_of_month,
+                month_of_year=self.month_of_year,
+                tz=self.timezone
+            )
+        return crontab
 
     @classmethod
     def from_schedule(cls, schedule):

django_celery_beat/schedulers.py

@@ -1,6 +1,7 @@
 """Beat Scheduler Implementation."""
 from __future__ import absolute_import, unicode_literals
 
+import datetime
 import logging
 
 from multiprocessing.util import Finalize
@@ -14,6 +15,7 @@
 from celery.utils.time import maybe_make_aware
 from kombu.utils.json import dumps, loads
 
+from django.conf import settings
 from django.db import transaction, close_old_connections
 from django.db.utils import DatabaseError, InterfaceError
 from django.core.exceptions import ObjectDoesNotExist
@@ -89,7 +91,13 @@ def __init__(self, model, app=None):
 
         if not model.last_run_at:
             model.last_run_at = self._default_now()
-        self.last_run_at = make_aware(model.last_run_at)
+
+        last_run_at = model.last_run_at
+
+        if settings.DJANGO_CELERY_BEAT_TZ_AWARE:
+            last_run_at = make_aware(last_run_at)
+
+        self.last_run_at = last_run_at
 
     def _disable(self, model):
         model.no_changes = True
@@ -125,7 +133,9 @@ def _default_now(self):
         # The PyTZ datetime must be localised for the Django-Celery-Beat
         # scheduler to work. Keep in mind that timezone arithmatic
         # with a localized timezone may be inaccurate.
-        return now.tzinfo.localize(now.replace(tzinfo=None))
+        if settings.DJANGO_CELERY_BEAT_TZ_AWARE:
+            now = now.tzinfo.localize(now.replace(tzinfo=None))
+        return now
 
     def __next__(self):
         self.model.last_run_at = self.app.now()
@@ -140,6 +150,10 @@ def save(self):
         obj = type(self.model)._default_manager.get(pk=self.model.pk)
         for field in self.save_fields:
             setattr(obj, field, getattr(self.model, field))
+
+        if not settings.DJANGO_CELERY_BEAT_TZ_AWARE:
+            obj.last_run_at = datetime.datetime.now()
+
         obj.save()
 
     @classmethod

t/proj/settings.py

@@ -122,3 +122,4 @@
 # https://docs.djangoproject.com/en/1.9/howto/static-files/
 
 STATIC_URL = '/static/'
+DJANGO_CELERY_BEAT_TZ_AWARE = True