'Test the custom ``django_date_extract method``, in particular against fields
which clash with strings passed to it (e.g. \'day\') (#12818).'

def test_django_date_extract(self):

    updated = datetime.datetime(2010, 2, 20)
    SchoolClass.objects.create(year=2009, last_updated=updated)
    classes = SchoolClass.objects.filter(last_updated__day=20)
    self.assertEqual(len(classes), 1)
