Ensured that explicit time zones are rejected by forms.

            self.assertTrue(form.is_valid())

            self.assertEqual(form.cleaned_data['dt'], datetime.datetime(2011, 9, 1, 10, 20, 30, tzinfo=UTC))

    def test_form_with_explicit_timezone(self):

        form = EventForm({'dt': '2011-09-01 17:20:30+07:00'})

        # Datetime inputs formats don't allow providing a time zone.

        self.assertFalse(form.is_valid())

    @skipIf(pytz is None, "this test requires pytz")

    def test_form_with_non_existent_time(self):

        with timezone.override(pytz.timezone('Europe/Paris')):