Java Programming

Here date and cal.getTime() return date in BST format. But my requirement is date should be converted to GMT format and then compared with cal.getTime() which is in BST format.

          Object o = timeStamp.get(TIMESTAMP_OBJECT);
            java.util.Date date = (java.util.Date) o;
            
                      
            Calendar cal = Calendar.getInstance();
            getBDO().setLastDespatch(isLastDespatch(cal.getTime(), date));
     
........
 public static boolean isLastDespatch(Date counterDate, Date lastDespatchDate)
    {
        if (counterDate.before(lastDespatchDate))
        {
            // last despatch timestamp before
            return false;
        }
        else
        {
            // last despatch timestamp expired, therefore tell clerk
            return true;
        }
    }

I tried

 
Object g = date.toGMTString();
 

But I am not able to convert this object to again Date...