title: Parsing a Datetime String into a Django DateTimeField
body: <p>I have a Django app with a model that contains a field of type DateTimeField.<br>
  I am pulling data from the web in the format of <code>2008-04-10 11:47:58-05</code>.<br>
  I believe that the last 3 characters in this example are the timezone.<br>
  How can I preserve that data in the DateTimeField, and is there an easy conversion between the two? Setting the DateTimeField to simply contain a string of the above format throws a ValidationError.  </p>
  
  <p>Thank you!</p>