One of the most uses I give to this command is to turn the PC off after some time, sure there are other ways.

I like the way you may execute batch jobs at a given time, all you need is:

1. Write your shell script

Which actually is a list of commands in a text file

2. Execute the at command

at now + 5 minutes < $HOME/listofcommands.txt

You can use times like "now", "noon", "midnight", or a date in the format of DD.MM.YY

check man at in order to have more details