title: How to get the time difference in talend?
body: <p>How to get the difference in time by comparing with the previous value and getting the result .Say for example 
  There are 
  2017-01-01 13:00:00
  2017-01-01 13:15:00</p>
  
  <p>I need the difference as 15 minutes after finding the difference,How to do it?</p>