At this time I will write about shutdown automatic in Linux, a very simple way of just setting the time, by using the Terminal (not the bus terminal).
This method can be used when we are working at night, are afraid to fall asleep and forget to turn off the computer, in order to save electricity and also extend the life of the computer, this method is quite effective. Here are the steps:
# shutdown -h 1:45, then press enter
# shutdown -c, then press enter.
For more details, you can read the manual shutdown
$ man shutdown.