Windows8 how to set up a timed shutdown

Sometimes we use to download things, or need to shut down in a specific time, how to do it?
1. With the help of software: timed shutdown 3000. The software is very simple and will not be described in detail.
2. Do it yourself.
Create a new file, named as shutdown.
Content is at 23:00 cmd.exe /c shutdown -s -t 30
Then modify the file name to shutdown.bat (note that the extension must be changed, before setting it to not hide the extension of known files) Name.)
Then put this file into the boot entry.
The meaning of this command is 23:00 shutdown, and there is a 30 second prompt.
You can also run shutdown -a to cancel the shutdown!