The website (http://support.apple.com/kb/HT1490) says "5. Turn off the computer or allow it to sleep for five hours or more.", does it have to sleep for exactly five hours or more? Or can it be much lesser? Because I have to go to sleep and I can't wait a little bit longer. Can I just leave the notebook sleeping overnight and then wake up and plug in the charger to charge the notebook or what? I don't the battery to mess up if I do anything wrong.