title: Want to convert EST to PST for given date in PHP
body: <p>Can we change date which is in EST to PST format...like any PHP function for that</p>
  
  <p>Ex <code>2012-11-28 08:00:00</code> which is EST to PST <code>2012-11-28 05:00:00</code></p>
  
  <p>I know that we can directly subtract 3 hrs from EST.
  But is there any PHP in built function which support it ?</p>