When the machine is off it is "dead" and so unable
to initiate any actions.
If your machine supports "wake on lan" or some
other BIOS feature allowing it to receive a signal
you may be able to devise a way for it to start on
a schedule.
Note: F1 may not be the key to access your BIOS settings. Consult your
computer's manual. You'll be looking for a setting such as "Wake on
alarm", or similar wording.