[:intro:] 

When going to sleep with my flash new pillow and headphones on I would sometimes wake up with the music still blaring,  I wanted something that would tell my pc to shut down in x hours to conserve energy, and cut the noise off after giving myself enough time to go to sleep.  There are a few shutdown timers out there, but they are quite bloaty and annoying - turns out it was pretty easy to make my own here is how I did it (in windows XP). [:question:] are there similar functions for other OS :[question]: 

:[intro]:

[:step:] Right click on your desktop and choose new from the menu, then shortcut from the second menu. :[step]:

[:step:] In the window that opens type (without the quotes) "shutdown.exe -s -f -t 5130"

The -s stands for shutdown (rather than restart or logout), the -f means force the shutdown so be sure to save your work because it will shutdown no matter what is open.  The -t is the time (in seconds) it will delay before shutting down.  You can calculate your time by timesing the number of minuites by 60 (1hr = 3600 seconds, 1 and a half hours = 5400 seconds ...etc). Click next and type the name you wish your shutdown shortcut to have, Click finish and you are done, just start this when you are sure you want to go to sleep, because to abort it isn't super easy.  :[step]:

[:step:] To abort the shutdown you can either make another shortcut like above but type "shutdown.exe -a" instead of the "shutdown.exe -s -f -t 5130" bit, or click the start menu, then run, and type "shutdown -a" in the little box that pops up.:[step]: 

If you are wondering about all the step, question, and intro bits, its part of a system I am trying to create for a standardized instruction exposed tagging format to compliment a microformat (some people may not know how to do microformats).  This will allow a user to submit a url to a central repository for all instruction type posts without having to re-enter all the info in forms, and the content can be originally hosted on their own site.  More on this as it develops.