title: Default value format on Django DateField
body: <p>I'm trying to specify a default date in a Django model, for example:</p>
  
  <pre><code>from datetime import date
  
  class A(models.Model):
      date = models.DateField(default=date.today())
  </code></pre>
  
  <p>This works and I can see the default date in a <code>ModelForm</code>, but when I change the form input_format to <code>%d-%m-%Y</code>, the default date never appears in the field.</p>
  
  <p>I've also tried:</p>
  
  <pre><code>from datetime import date
  
  class A(models.Model):
      date = models.DateField(default=date.today().strftime('%d-%m-%Y'))
  </code></pre>
  
  <p>This doesn't work either. Can anyone help me?</p>