title: Android how to get time difference between two time zones in android?
body: <p>I need to get time difference between two dates in different time zones. Currently I am doing this:</p>
  
  <pre><code>Calendar c1=Calendar.getInstance(TimeZone.getTimeZone("EDT"));
  Calendar c2=Calendar.getInstance(TimeZone.getTimeZone("GMT"));
  String diff=((c2.getTimeInMillis()-c1.getTimeInMillis())/(1000*60*60))+" hours";
  new AlertDialog.Builder(this).setMessage(diff).create().show();
  </code></pre>
  
  <p>I get <code>0</code> hours. What am I doing wrong?</p>