I was reading through a mac magazine in a book store today and there was a mention of leaving your computer on until 3:15 am because that is what UNIX does for a self reboot or something like that. since old unix computers used to be on 24 hours a day. I am probably completely wrong and my memory is ill serving me, so I am curious about what it really is, what I should do, if I should do anything. On the chance what I am thinking is right and that since I am not usually up at 3:15 am, I could just change my clock at 3pm and then let it do what it needs to do. I have onyx, I am noticing a small decline in my system speed after a few months and want to try something.