how do you set the clock on a 89 firebird formula

 

If the radio is similar to the stock head unit in my '88 Trans Am, just turn off the radio, and then hit the "set" button. You then use the "scan" button to change the time by the hour and the "seek" button to change the time by the minute. Push one time quickly for each increment. The hours/minutes will increase by one with each push. If you need to set the time back, you will need to go all the way around as there is not a way to go down or back in time.

This is a photo of my head unit. The set button is small and by itself to the right of the 4 preset radio station selection buttons.