Monterrey is in Mexico and is currently on UTC-6. Its time zone is America/Monterrey.
Monterrey does not observe daylight saving time. It stays on UTC-6 all year, so the difference to any other place that also holds a fixed offset never changes.
The weekend in Monterrey falls on Saturday and Sunday. A working day of 9:00 AM to 6:00 PM is the assumption used on the board.
See the current time across Mexico, including the other cities Meridian tracks there and the time zones they use.