GM Service Manual Online
For 1990-2009 cars only

Press and hold HR until the correct hour appears on the display. The letters AM or PM will also appear. Then, press and hold MN until the correct minute appears on the display. The time may be set with the ignition on or off.

To synchronize the time with an FM station broadcasting Radio Data System (RDS) information, press and hold HR and MN at the same time until UPDATED appears on the display. If the time is not available from the station, NO UPDATE will appear on the display instead.