for the e30 computer - to set the clock there should be an hour and a minute button If i remember correctly you have to press them both and hold them until the period (.) starts to blink then press the proper button until the time is set then press the time button. I think this is right but i'm away from my car for 2 weeks so I can't go out and make sure. otherwise its some combination of those two and maybe pressing the time button. Hope this helps.