title: Calculate diff. between two times given that we have two different strings for time and date
body: <p>I have time data split in two strings - one string for date, and one for time.<br>
  I want to calculate the diff. of such two times in Java.<br>
  e.g.   </p>
  
  <ul>
  <li>time 1:"26/02/2011" and "11:00 AM"  </li>
  <li>time 2:"27/02/2011" and "12:15 AM"  </li>
  </ul>
  
  <p>Difference would be like 13 hours 15 minutes.</p>