title: How is timezone EST different from EST5EDT?
body: <p>How different is EST from EST5EDT ? Isn't EST take into account DST?</p>
  
  <p>I wrote a small java snippet to figure out the difference and output says EST5EDT takes in to account DST while EST does not</p>
  
  <pre><code>SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss.SSS"); 
  dateFormat.setTimeZone(TimeZone.getTimeZone("EST5EDT")); 
  System.out.println("EST5EDT" +dateFormat.format(new Date()));
      /* prints EST5EDT2013-Apr-05 02:24:16.471 */  
  
  
  dateFormat = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss.SSS"); 
  dateFormat.setTimeZone(TimeZone.getTimeZone("EST")); 
  System.out.println("EST "+dateFormat.format(new Date()));
     /*prints EST 2013-Apr-05 01:24:16.472 */
  </code></pre>
  
  <p>But the below snippet produced shocking output</p>
  
  <pre><code>System.out.println("EST5EDT offset "+TimeZone.getTimeZone("EST5EDT").getRawOffset()/(60*60*1000));
  /* prints 5 instead of 4 (DST) */
  </code></pre>
  
  <p>Could someone please explain what exactly is happening here ? why is getRawOffset returning 5 instead of 4 ? How to get timezone offset with DST?</p>