Restarting from time to time OS X manages the whole system. Then I am sure the sleep mode still use energy. Thus my question. I am sure starting also uses much energy too. This is why I wonder what is the minimum of time away justifying shutting down.

Everybody knows that while asleep the Mac use "very little energy" Very little is like saying about next week, maybe tomorrow... Do you know how much energy is saved by shutting down and how much extra energy is used to restart the Mac? If so, what is the minimum of time away from the Mac making it worth a shit down? That is the question.

My iMac shuts down if the time I choose is in the morning like 8, 9 AM. If I choose 12:30, 1AM, 2AM the Mac refuses to shut down. I have Apple care. They could not help. I was advise to bring the Mac to the Genius bar. I did. 3 hours later we were sure it might work. It doesn't. That is a bug Apple should know about. How do you report this to Apple?

By the way "Not using much energy while asleep" what does it mean? Is it the usual wasteful ways that has brought us to the situation we are in regarding energy? We all have to make our part to save energy and this includes shutting the Mac when no in use.

10.4.11 iMac G5 if anyone cares to know.