Simple Shutdown Timer is a freeware tool that lets shutdown, log off, reboot, hibernate or sleep your PC, after a specific time. The program is pretty self-explanatory. You need to put in the time and select the desired power options from the drop-down list and click start to make it effective. When the time reaches 0, the computer will be powered off.
This portable app supports two command lines:
The above command will put the system into standby mode immediately.
Above command will tell the program to set the time for 4 hours and 30 mins. and 0 sec. and to start the countdown.
Simple Shutdown Timer is a few KBs in size, you can download it from here.
Ninja Shutdown is another free program that lets you schedule Shutdown, Restart or Log Off. It has some additional features, like remote shutdown. Also, it supports Windows 10. You can download it from here.
You might be interested in Windows Reboot freeware app.