By the time you hit 22 (or 21 if you've had a head start on life) your 24 hour days would/should probably be split 50-50 between your home and your office.
12 hours here. 12 hours there.
Anything else you need to do during your day or night will have to take up time that is originally dedicated to either.
This is exactly where your life choices are concieved. That's how you put together your priorities.