I think I understand what he means. If he's anything like my current situation, he may have about 7 hours of free time split in two - the issue is that most of everything I want to do would take four to six hours in a single block (or maybe, like me, there's some things that COULD be done in separate blocks but there's momentum - when I start something and am unable to finish it before I have to change activities, it's infuriating). So what he meant by "needing more downtime than most people need sleep" is that he has plans and ideas, and just like sleep - two four-hour blocks is just not the same as one eight-hour block. (As you mentioned, I COULD start working 7-4 - but the day team here sucks major ass. My ideal time would actually be 2AM-11PM so that I would have some solid time where I can do shit without bothering people who want to sleep)