UHH I think it's been varying a lot lately. For a bit there I was spending far too much time drawing (I was getting out of bed at like 8am, immediately go to my computer, sit down, draw until 2am, and then go back to sleep. With small food breaks inbetween but not much else, not even conversation. I don't recommend anyone do that at all, even if you're just trying to keep yourself as busy as possible like I was)
Right now I'm working on getting a healthier schedule, finding other things I can keep myself busy with as well as art so I for one, don't burn myself out, and for two, am taking better care of myself (doing stuff like going outisde, taking walks, riding my bike, etc.). My goal is to get it to more about 4-8 hours and actually allow myself time to do other things like play games.