  from django.db import models
  from django.test import TestCase
  from django.core import validators
  from rest_framework import serializers
  
  
  class TimestampedModel(models.Model):
 
</s> remove         msg = self.error_messages['invalid'] % value
 </s> add         date_input_formats = '; '.join(self.format)
        msg = self.error_messages['invalid'] % get_readable_date_format(date_input_formats) </s> remove         try:
            parsed = parse_date(value)
            if parsed is not None:
                return datetime.datetime(parsed.year, parsed.month, parsed.day)
        except (ValueError, TypeError):
            msg = self.error_messages['invalid_date'] % value
            raise ValidationError(msg)

        msg = self.error_messages['invalid'] % value
 </s> add         datetime_input_formats = '; '.join(self.format)
        msg = self.error_messages['invalid'] % get_readable_date_format(datetime_input_formats)
from django.utils import unittest

  from django.db import models
  from django.test import TestCase
  from django.core import validators
from django.utils import unittest

  from rest_framework import serializers
  
  
  class TimestampedModel(models.Model):
keep keep add keep keep keep keep
 Add better date / datetime validation (pull 2)

addition to #631 with update to master + timefield support 
rest_framework/tests/fields.py