I want to convert this GMT time stamp to GMT+13:
2011-10-06 03:35:05
I have tried about 100 different combinations of DateFormat, TimeZone,
Your approach works without any modification.
Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
// Timestamp for 2011-10-06 03:35:05 GMT
calendar.setTime(new Date(1317872105000L));
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z");
formatter.setTimeZone(TimeZone.getTimeZone("GMT+13"));
// Prints 2011-10-06 16:35:05 GMT+13:00
System.out.println(formatter.format(calendar.getTime()));