title: add missing time interval in hourly data
body: <p>I am looking for solution to add the missing time interval</p>
  
  <p>Sample hourly data with missing hour</p>
  
  <pre>
  06.19.2011 00:00:00
  06.19.2011 01:00:00
  06.19.2011 02:00:00
  06.19.2011 03:00:00
  06.19.2011 04:00:00
  06.19.2011 05:00:00
  06.19.2011 07:00:00
  06.19.2011 08:00:00
  </pre>
  
  <p>sample hourly data with two missing hours</p>
  
  <pre>
  06.19.2011 00:00:00
  06.19.2011 01:00:00
  06.19.2011 02:00:00
  06.19.2011 05:00:00
  06.19.2011 07:00:00
  06.19.2011 08:00:00
  </pre>
  
  <p>So missing intervals need to be inserted to keep dynamic charts accurate</p>
  
  <pre>
  06.19.2011 03:00:00
  06.19.2011 04:00:00
  </pre>