Guam is in Guam and is currently on UTC+10. Its time zone is Pacific/Guam.
Guam does not observe daylight saving time. It stays on UTC+10 all year, so the difference to any other place that also holds a fixed offset never changes.
The weekend in Guam falls on Saturday and Sunday. A working day of 9:00 AM to 6:00 PM is the assumption used on the board.