I don't have one either, but I found this for a 91'. It may be the same:
Click on the "Set" button, then I think it was the scan & seek buttons to alter the time (ones above the clock display). One controls the hour the other controls the seconds. Keep pressing in the button to move the time ahead (once it hits 12 or 60 it will go to 1, 2, 3... ). When the time is right press the "Set" button again.