title: Convert the unicode to datetime format
body: <p>A function returns date and time in unicode format.</p>
  
  <pre><code> u'2014-03-06T04:38:51Z'
  </code></pre>
  
  <p>I wish to convert this to date and time format and subtract it with current datetime to get the number of days in between.</p>
  
  <p>Thanks in advance</p>