Not long ago I had a program that would shut down the computer at a specified time, or whatever. All I can really describe is that it had a countdown thing in the bottom right corner of the screen with green numbers and a black background, and a password option. I don't remember the name of the program, and I need it for tonight. I've already tried Googling some stuff like auto shutdown, but I can't find it.
You can schedule your compy to shut down with Task Scheduler.