      empty = None
  
      def from_native(self, value):
          if value in validators.EMPTY_VALUES:
              return None
  
 
</s> remove         'invalid': _("'%s' value has an invalid format. It must be a valid "
                     "time in the HH:MM[:ss[.uuuuuu]] format."),
 </s> add         'invalid': _(u"Time has wrong format. Use one of these formats instead: %s"), </s> remove         'invalid': _("'%s' value has an invalid date format. It must be "
                     "in YYYY-MM-DD format."),
        'invalid_date': _("'%s' value has the correct format (YYYY-MM-DD) "
                          "but it is an invalid date."),
 </s> add         'invalid': _(u"Date has wrong format. Use one of these formats instead: %s"), </s> remove         'invalid': _("'%s' value has an invalid format. It must be in "
                     "YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."),
        'invalid_date': _("'%s' value has the correct format "
                          "(YYYY-MM-DD) but it is an invalid date."),
        'invalid_datetime': _("'%s' value has the correct format "
                              "(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) "
                              "but it is an invalid date/time."),
 </s> add         'invalid': _(u"Datetime has wrong format. Use one of these formats instead: %s"),
    def __init__(self, *args, **kwargs):
        self.format = kwargs.pop('format', settings.DATETIME_INPUT_FORMATS)
        super(DateTimeField, self).__init__(*args, **kwargs)

      empty = None
  
    def __init__(self, *args, **kwargs):
        self.format = kwargs.pop('format', settings.DATETIME_INPUT_FORMATS)
        super(DateTimeField, self).__init__(*args, **kwargs)

      def from_native(self, value):
          if value in validators.EMPTY_VALUES:
              return None
  
keep add keep keep keep keep
 Add better date / datetime validation (pull 2)

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