Have a look at your Computer's BIOS. Most BIOS have the feature
(RTC) to turn ON the system at a given time. I have been using this
feature for quite a few years now.
My PC does have this ALARM function.
I setup the alarm, but the PC did not boot at the set time.
Should I be shutting down the PC in any specific manner.
I did a standard `shutdown -h now`