// the GMT offset is in seconds.
// for example, America/Los_Angeles, -28800
System.out.println("GmtOffset:" + tz.getGmtOffset());
System.out.println("Description:" + tz.getDescription());
Calendar curTime = si.currentTime();
System.out.println("\nCurrent time:" + curTime.getTime());
//roll back one hour
curTime.roll(Calendar.HOUR, false);
hdts.updateDateTime(curTime);