Many options, one option is to create a scheduled task and run program. Now if you're talking about many systems than what you can do is use psexec @file shutdown blah blah blah and schedule that at 8:30.
How To Use the Remote Shutdown Tool to Shut Down and Restart a Computer in Windows 2000
http://support.microsoft.com/kb/317371
James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com
