title: Java: How to add seconds to Timestamp?
body: <p>I fail to add seconds to Java Timestamp.</p>
  
  <p>I have this, but, it gives me the same date:</p>
  
  <pre><code>int sec = 600;
  
  java.sql.Timestamp ts_from_ws = new java.sql.Timestamp(retry_date);
  Calendar cal = Calendar.getInstance();
  cal.setTimeInMillis(ts_from_ws.getTime());
  cal.add(Calendar.SECOND,sec);
  java.sql.Timestamp ts_new_date_ws = new java.sql.Timestamp(cal.getTime().getTime());
  </code></pre>