      def test_valid_custom_date_time_input_formats(self):
          serializer = DateTimeObjectCustomFormatSerializer(data={'date_time': '1984'})
          self.assertTrue(serializer.is_valid())
  
          serializer = DateTimeObjectCustomFormatSerializer(data={'date_time': '1984 04:31'})
          self.assertTrue(serializer.is_valid())
  
      @unittest.skipUnless(django.VERSION >= (1, 4), "django < 1.4 don't have microseconds in default settings")
      def test_wrong_default_date_time_input_format_for_django_gte_1_4(self):
          serializer = DateTimeObjectSerializer(data={'date_time': 'something wrong'})
          self.assertFalse(serializer.is_valid())
 
</s> remove     def test_valid_custom_date_time_input_formats(self):
        serializer = DateTimeObjectCustomFormatSerializer(data={'date_time': '1984'})
        self.assertTrue(serializer.is_valid())
 </s> add class DateTimeFieldTest(TestCase):
    """
    Tests for the DateTimeField from_native() and to_native() behavior
    """ </s> remove     @unittest.skipUnless(django.VERSION >= (1, 4), "django < 1.4 don't have microseconds in default settings")
    def test_wrong_default_date_time_input_format_for_django_gte_1_4(self):
        serializer = DateTimeObjectSerializer(data={'date_time': 'something wrong'})
        self.assertFalse(serializer.is_valid())
        self.assertEquals(serializer.errors, {'date_time': ['Datetime has wrong format. Use one of these formats instead: '
                                                            'YYYY-MM-DD HH:MM:SS; YYYY-MM-DD HH:MM:SS.uuuuuu; YYYY-MM-DD HH:MM; '
                                                            'YYYY-MM-DD; MM/DD/YYYY HH:MM:SS; MM/DD/YYYY HH:MM:SS.uuuuuu; '
                                                            'MM/DD/YYYY HH:MM; MM/DD/YYYY; MM/DD/YY HH:MM:SS; '
                                                            'MM/DD/YY HH:MM:SS.uuuuuu; MM/DD/YY HH:MM; MM/DD/YY']})
 </s> add         self.assertEqual(datetime.datetime(1984, 7, 31), result_1)
        self.assertEqual(datetime.datetime(1984, 7, 31, 4, 31), result_2)
        self.assertEqual(datetime.datetime(1984, 7, 31, 4, 31, 59), result_3)
        self.assertEqual(datetime.datetime(1984, 7, 31, 4, 31, 59, 200), result_4) </s> remove         serializer = DateTimeObjectSerializer(data={'date_time': '07/31/84 04:31'})
        self.assertTrue(serializer.is_valid())
 </s> add         self.assertEqual('1984-07-31', result_1) </s> remove     @unittest.skipUnless(django.VERSION >= (1, 4), "django < 1.4 don't have microseconds in default settings")
    def test_valid_default_date_time_input_formats_for_django_gte_1_4(self):
        serializer = DateTimeObjectSerializer(data={'date_time': '1984-07-31 04:31:59.123456'})
        self.assertTrue(serializer.is_valid())
 </s> add         result_1 = f.to_native(datetime.date(1984, 7, 31)) </s> remove         serializer = DateTimeObjectSerializer(data={'date_time': '07/31/84'})
        self.assertTrue(serializer.is_valid())
 </s> add     def test_to_native_custom_format(self):
        """
        Make sure to_native() returns correct custom format.
        """
        f = serializers.DateField(output_format="%Y - %m.%d")
    def test_from_native_string(self):
        """
        Make sure from_native() accepts default iso input formats.
        """
        f = serializers.DateTimeField()
        result_1 = f.from_native('1984-07-31')
        result_2 = f.from_native('1984-07-31 04:31')
        result_3 = f.from_native('1984-07-31 04:31:59')
        result_4 = f.from_native('1984-07-31 04:31:59.000200')
      def test_valid_custom_date_time_input_formats(self):
          serializer = DateTimeObjectCustomFormatSerializer(data={'date_time': '1984'})
          self.assertTrue(serializer.is_valid())
  
    def test_from_native_string(self):
        """
        Make sure from_native() accepts default iso input formats.
        """
        f = serializers.DateTimeField()
        result_1 = f.from_native('1984-07-31')
        result_2 = f.from_native('1984-07-31 04:31')
        result_3 = f.from_native('1984-07-31 04:31:59')
        result_4 = f.from_native('1984-07-31 04:31:59.000200')
    def test_from_native_string(self):
        """
        Make sure from_native() accepts default iso input formats.
        """
        f = serializers.DateTimeField()
        result_1 = f.from_native('1984-07-31')
        result_2 = f.from_native('1984-07-31 04:31')
        result_3 = f.from_native('1984-07-31 04:31:59')
        result_4 = f.from_native('1984-07-31 04:31:59.000200')
  
      @unittest.skipUnless(django.VERSION >= (1, 4), "django < 1.4 don't have microseconds in default settings")
      def test_wrong_default_date_time_input_format_for_django_gte_1_4(self):
          serializer = DateTimeObjectSerializer(data={'date_time': 'something wrong'})
          self.assertFalse(serializer.is_valid())
keep keep keep keep replace replace keep keep keep keep keep
 Add drf settings + output format + testcases 
rest_framework/tests/fields.py