Alternate Shutdown is a freeware app that can shut down your computer after a period of time or at a specific date/time setting.
It also offers the possibility to restart the computer after being shut down or sending the computer into hibernation. You may also choose a force parameter that will close running applications that are hanging.
The program may be shown as a tray icon to avoid using space in the taskbar if the shutdown time is set to a more extended period.
Be sure to save all your data before using this program. You are using it at your own risk.