Drat! I meant the clock on the radio.

Depending on what radio u have, I have an ac/delco stock, the easiest way for me to do it, is with radio off and the clock showing the time, then hit the "set" buuton, it should now show the word set by the time, then have to hit the "scan" and "seek" buttons, one does the hours and the other does the minutes, then when it is set right, hit the "set" button again.