My solution to exhaustion is that I reverse day/night twice. I don't play during the day and keep my game on pause. When I get home from work I unpause the game and switch day/night. Around 11 pm I switch day/night back to normal so they can sleep overnight and get refreshed (which seems to happen between 2 am and 6 am somehow)but keep the game running. The next morning I pause the game again.