title: How To Get The Total Time In Hrs
body: <p>I have A table named tblMaintainsHdr
  In that i have The Following Columns</p>
  
  <pre>
  asset_ID maintns_StrtDate Maintns_EndDate  Maintains_strtTime      Maintains_EndTime
  
   1       2011-12-09       2011-12-09     2011-12-09 12:03:00.000   2011-12-09 12:03:00.000
   2       2011-12-10       2011-12-12     2011-12-10 12:03:00.000   2011-12-12 12:03:00.000
   </pre>
  
  <p>I need to calculate The Total Maintainenance Hrs considering the columns <br> </p>
  
  <p><code>maintains start time</code>, <code>maintains end time</code>, <code>maintains start date</code>, <code>maintains end date</code></p>