title: django datetime to unix timestamp
body: <p>my model </p>
  
  <pre><code>create = models.DateTimeField(auto_now_add=True)
  </code></pre>
  
  <p>how to get unix time from this field?</p>
  
  <pre><code>datetime.datetime.timestamp()
  </code></pre>
  
  <p>but I need int</p>