>>> DateField( settings.DATE_INPUT_FORMATS).to_python("Jan 01 2010")
datetime.date(2010, 1, 1)
>>> DateField( ).to_python("Jan 01 2010")
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "C:\python26\lib\site-packages\django\forms\fields.py", line 345, in to_python
    raise ValidationError(self.error_messages['invalid'])
ValidationError: [u'Enter a valid date.']