13 hours here, then the next day I was screwed to a major migraine and temporary partial blindness, took 2 days to stop feeling like death. Take it from me, 3 days on a roller-coaster, literally throwing up, impaired vision and a headache so bad you can hardly move is not fun. The sun does the same thing in less time which is one of the reasons I hate it.
There is no way I can go past 13 hours, I am not doing that again.
My custom built computer (by a relative for me because I'm dumb) has a great fan, it's never overheated but I don't have infinite resources. It does and will freeze up if I spawn too many chickens. Maybe one day I will record myself spawning chickens until my game crashes. Sounds like a fun experiment.