title: Date object to Calendar [Java]
body: <p>I have a class Movie
  in it i have a start Date, a duration and a stop Date.
  Start and stop Date are Date Objects (private Date startDate ...)
  (It's an assignment so i cant change that)
  now I want to automatically calculate the stopDate by adding the duration (in min) to the startDate.</p>
  
  <p>By my knowledge working with the time manipulating functions of Date is deprecated hence bad practice but on the other side i see no way to convert the Date object to a calendar object in order to manipulate the time and reconvert it to a Date object.
  Is there a way? And if there is what would be best practice</p>