Fixed #1480 -- Added the ability to use the system timezone. Thanks to Ramiro Morales for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12602 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/conf/__init__.py

@@ -102,7 +102,7 @@ class Settings(object):
                 new_installed_apps.append(app)
         self.INSTALLED_APPS = new_installed_apps
 
-        if hasattr(time, 'tzset'):
+        if hasattr(time, 'tzset') and getattr(self, 'TIME_ZONE'):
             # Move the time zone info into os.environ. See ticket #2315 for why
             # we don't do this unconditionally (breaks Windows).
             os.environ['TZ'] = self.TIME_ZONE

django/conf/project_template/settings.py

@@ -23,6 +23,8 @@ DATABASES = {
 # Local time zone for this installation. Choices can be found here:
 # http://en.wikipedia.org/wiki/List_of_tz_zones_by_name
 # although not all choices may be available on all operating systems.
+# On Unix systems, a value of None will cause Django to use the same
+# timezone as the operating system.
 # If running in a Windows environment this must be set to the same as your
 # system time zone.
 TIME_ZONE = 'America/Chicago'

django/db/backends/postgresql/base.py

@@ -119,7 +119,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         set_tz = False
         settings_dict = self.settings_dict
         if self.connection is None:
-            set_tz = True
+            set_tz = settings_dict.get('TIME_ZONE')
             if settings_dict['NAME'] == '':
                 from django.core.exceptions import ImproperlyConfigured
                 raise ImproperlyConfigured("You need to specify NAME in your Django settings file.")

django/db/backends/postgresql_psycopg2/base.py

@@ -113,7 +113,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         set_tz = False
         settings_dict = self.settings_dict
         if self.connection is None:
-            set_tz = True
+            set_tz = settings_dict.get('TIME_ZONE')
             if settings_dict['NAME'] == '':
                 from django.core.exceptions import ImproperlyConfigured
                 raise ImproperlyConfigured("You need to specify NAME in your Django settings file.")

docs/ref/settings.txt

@@ -1505,28 +1505,42 @@ TIME_ZONE
 
 Default: ``'America/Chicago'``
 
-A string representing the time zone for this installation. `See available choices`_.
-(Note that list of available choices lists more than one on the same line;
-you'll want to use just one of the choices for a given time zone. For instance,
-one line says ``'Europe/London GB GB-Eire'``, but you should use the first bit
-of that -- ``'Europe/London'`` -- as your ``TIME_ZONE`` setting.)
+.. versionchanged:: 1.2
+   ``None`` was added as an allowed value.
 
-Note that this is the time zone to which Django will convert all dates/times --
-not necessarily the timezone of the server. For example, one server may serve
-multiple Django-powered sites, each with a separate time-zone setting.
+A string representing the time zone for this installation, or
+``None``. `See available choices`_. (Note that list of available
+choices lists more than one on the same line; you'll want to use just
+one of the choices for a given time zone. For instance, one line says
+``'Europe/London GB GB-Eire'``, but you should use the first bit of
+that -- ``'Europe/London'`` -- as your ``TIME_ZONE`` setting.)
 
-Normally, Django sets the ``os.environ['TZ']`` variable to the time zone you
-specify in the ``TIME_ZONE`` setting. Thus, all your views and models will
-automatically operate in the correct time zone. However, if you're manually
-:ref:`manually configuring settings
-<settings-without-django-settings-module>`, Django will *not* touch the ``TZ``
-environment variable, and it'll be up to you to ensure your processes are
-running in the correct environment.
+Note that this is the time zone to which Django will convert all
+dates/times -- not necessarily the timezone of the server. For
+example, one server may serve multiple Django-powered sites, each with
+a separate time-zone setting.
+
+Normally, Django sets the ``os.environ['TZ']`` variable to the time
+zone you specify in the ``TIME_ZONE`` setting. Thus, all your views
+and models will automatically operate in the correct time zone.
+However, Django won't set the ``TZ`` environment variable under the
+following conditions:
+
+ * If you're using the manual configuration option as described in
+   :ref:`manually configuring settings
+   <settings-without-django-settings-module>`, or
+
+ * If you specify ``TIME_ZONE = None``. This will cause Django to fall
+   back to using the system timezone.
+
+If Django doesn't set the ``TZ`` environment variable, it's up to you
+to ensure your processes are running in the correct environment.
 
 .. note::
-    Django cannot reliably use alternate time zones in a Windows environment.
-    If you're running Django on Windows, this variable must be set to match the
-    system timezone.
+    Django cannot reliably use alternate time zones in a Windows
+    environment. If you're running Django on Windows, this variable
+    must be set to match the system timezone.
+
 
 .. _See available choices: http://www.postgresql.org/docs/8.1/static/datetime-keywords.html#DATETIME-TIMEZONE-SET-TABLE
 

tests/regressiontests/app_loading/tests.py

@@ -19,7 +19,7 @@ Test the globbing of INSTALLED_APPS.
 >>> sys.path = old_sys_path
 
 # Undo a side-effect of installing a new settings object.
->>> if hasattr(time, "tzset"):
+>>> if hasattr(time, "tzset") and old_tz:
 ...     os.environ["TZ"] = old_tz
 ...     time.tzset()