title: How to subtract these two dates in Django/python?
body: <p>I get start_date like this: <code>start_date1 = datetime.datetime.utcnow().replace(tzinfo=utc)</code></p>
  
  <p>and pass end_date as a function argument like this:</p>
  
  <pre><code>a(datetime.datetime.utcnow().replace(tzinfo=utc))
  </code></pre>
  
  <p>They both are stored in database under <code>start_date and end_date</code> coloum name.</p>
  
  <p>What I am trying to do is subtract end_date and start_date to get duration:</p>
  
  <pre><code>  start_date = [i.start_date for i in b ]
    end_date = [i.end_date for i in b ]
  </code></pre>
  
  <p>I would use this to subtract those two dates: <code>t = [i - j for i, j in zip(y, x)]</code></p>
  
  <p>However the problem is start_date and end_date are returned in unicodes. I can't convert them into datetime format again. What should I do?</p>