title: How to make a class immutable with Date object in it?
body: <p>This is just from an academic learning point of view. All I know is that whenever we want to make some class immutable, 
  - it has to consist of final primitive fields
  - reference does not escapes during construction of object
  - if uses other objects, then those objects need to be recursively immutable too or API immutable classes like java.lang.String, among some other detailed lookouts!</p>
  
  <p>But I recently came accross a question wherein an interviewer asked a candidate to create an immutable class that has a java.util.Date in it. My first impression tells that its not possible although we can do workarounds with String containing the date string rather than in Date object itself.</p>
  
  <p>Please clarify me on this. Thank you.</p>