What Happens if the Computer is Off When the Scheduled Install Time Passes?

What happens if the Computer is off when the Scheduled Install time passes? Does the OS just notice it was supposed to have installed updates and do it at that moment, or does it wait for the next scheduled time to try and update again?

I'm trying to find the best time to have these install and my biggest concern is that if I pick a time during the day and the user leaves documents open while they are away from their desks, and the updates try and install, it will reboot and they will lose their work. I was hoping I could set it up to run at 6am once a week, and most people will either

a) have left their PC's on overnight so the update will occur or
b) the first thing that happens when boot-up around 8am or so is the update will see it was supposed to have tried to install updates at 6am and instantly start since that time had passed.

Contributed by Wayne Flynn
If the computer is off during the scheduled install, when the computer is turned on, the installation is set for the next scheduled install. So if you set the install to happen every night at 23:00 and your users turn their machines off every night, they will NEVER get the update installed unless you're using SP1 that includes a new version of WUAU.ADM.

The new WUAU.ADM template has an option to schedule a "missed install" for a certain number of minutes after the computer is turned on. So, you could set it for 1 minute after power-on and the install would happen immediately, probably before the user can finish logging on.

The other, very cool, option in the SP1 version of WUAU.ADM is it provides a no-reboot option. Basically, the install will occur, but the machine will not finish it's install until a logoff (I think) or until the user manually performs a reboot.