title: Django forms: get the value of a forms.CharField as a date
body: <p>I have a form that has a CharField input for an european date.</p>
  
  <p>I need to transform it to a date python object.</p>
  
  <p>Is there a way to let the form care about it, in the validation? some callback? </p>
  
  <p>I don't want to do it in the view when there's the form processing.</p>