Update a few tests to use UTC instead of no TZ

tests/test_filtering.py

@@ -1642,13 +1642,11 @@ class Meta:
         self.assertQuerysetEqual(f.qs, [2], lambda o: o.pk)
 
 
-# use naive datetimes, as pytz is required to perform
-# date lookups when timezones are involved.
-@override_settings(USE_TZ=False)
+@override_settings(TIME_ZONE='UTC')
 class TransformedQueryExpressionFilterTests(TestCase):
 
     def test_filtering(self):
-        now_dt = datetime.datetime.now()
+        now_dt = now()
         after_5pm = now_dt.replace(hour=18)
         before_5pm = now_dt.replace(hour=16)
 
@@ -1667,9 +1665,7 @@ class Meta:
         self.assertQuerysetEqual(f.qs, [a.pk], lambda o: o.pk)
 
 
-# use naive datetimes, as pytz is required to perform
-# date lookups when timezones are involved.
-@override_settings(USE_TZ=False)
+@override_settings(TIME_ZONE='UTC')
 class CSVFilterTests(TestCase):
 
     def setUp(self):
@@ -1678,7 +1674,7 @@ def setUp(self):
         User.objects.create(username='aaron', status=2)
         User.objects.create(username='carl', status=0)
 
-        now_dt = datetime.datetime.now()
+        now_dt = now()
         after_5pm = now_dt.replace(hour=18)
         before_5pm = now_dt.replace(hour=16)