title: Add number of days to date field in spark scala Velocity
body: <p>Can anyone tell how to add days to already existing days.Example: I want to add 30 days to start date and i want to get it printed.
  I am trying this </p>
  
  <pre><code>set( $pageParameters.wiEndDate = ($pageParameters.wiStartDate+ 30))
  </code></pre>
  
  <p>But it is not working. Can anyone tell is there any API or how to get?
  Thank you</p>