title: Java Calendar: Subtract two Dates to get difference in days between the two
body: <p>I want to check how many days it has been since my user logged in:</p>
  
  <pre><code>Calendar lastLogin = Calendar.getInstance();
  lastLogin.setTime(randomPlayer.getLastLogin());
  Calendar today = Calendar.getInstance();
  </code></pre>
  
  <p>How would I subtract this to get the difference in days between the two? I.e number of days since last login. </p>