Hi you may want to start your computer automatically at some specific time [say at 2:00 am you want your pc to start automatically and at 6:00 you want your pc to shut down automatically] So this is possible using AUTO POWER ON AND SHUT DOWN software.
so first you have to dowanload this software after downloading and installing you may find it like this one given in picture but without any scheduled tasks forst click on new and then u will find something the picture below and then check "power on" option. and set your time .again u click on new task this time it is for automatic shutdown.so you need to check "Shut down" button and then again set the time thats it...your are done .So don't exit this application ..application must be running in background by checking your right corner of taskbar.
IMPORTANT:-Whenevr you left your pc instead of shut down use "Hibernate option".it will shut down hardisk,Fan,monitor.