title: Set start and end date in calendar using number of days
body: <p>I am newbie in Android. I would like to use Calendar and set start and end date. Problem is, that i know only start date(today's date),but the end date is dynamically and is based on number of days. So for example: i've got int= 400 days and the end date should be something like that: start date + 400. How can i do it?</p>
  <p><strong>P.S</strong> Ideally would be if start and end date will be range.</p>