I often do 6 hours, but not by intention, just because I get in the zone, but then my next day is totalled (have to go to bed early). I shoot for 8 or even 9 ho

I often do 6 hours, but not by intention, just because I get in the zone, but then my next day is totalled (have to go to bed early). I shoot for 8 or even 9 hours when I can get it. I also drink coffee in the evening sometimes but try not to exceed 300mg of caffeine per day, but I am weird in that I can sleep even while caffeine is running through my system. Mostly, I try to compact time as much as possible to free up a contiguous chunk to work on my own stuff, which is usually about 1 productive hour per day if I am lucky.