So I was done with my computer for the night, but wanted to use it to listen to some music while I pass out. So me being me, I decided that I'd look up how to shut it down on a timer. So here's how it's done (this is for PC's by the way, I'm pretty sure this won't work on a MAC OS):
Right click on your desktop (anywhere)
Go to New > Shortcut
In the text field for "What item would you like to create a shortcut for?" type in this: "shutdown -s -t 1800" without the " ". (The number is in seconds. 1800 seconds = 30 minutes)
Click next. Now, name it!
If you want to change the time at some point, you can right click the shortcut and click "Properties" and change the number to whatever time you want.
Now when you double click it, you'll now have an awesome new shutdown timer!
Now lets say you click it and now you're sitting there going "Shit! I don't want it to shut down in 30 minutes?!" Well, we have a fix for this.
First, right click your desktop and go to New > Shortcut
In the text field for "What item would you like to create a shortcut for?" type in this: "shutdown -a"
Click next and name it!
This will make it so you can stop the countdown whenever you want.
Well, have fun guys!