Since installing Leopard I have been using this widget to perform system maintenance by clicking on the various categories:
But a friend and I have noticed even when we skip a day or two of using the widget to perform the maintenance, that it shows the maintenance has been automatically performed, and that goes for daily, weekly and monthly. Which leads us to the conclusion that Leopard has made the adjustment to perform system maintenance soon after a boot up.
Just thought others would like to know this.

Just thought others would like to know this.