Completely depends on the days I am free
Sometimes I can play all day while listening to music, those are my zen days... Very relaxing and peaceful; usually the best days to focus on my games.
On busy days I usually play around 1-2 hours, sometimes more if I find time between tasks.
On losing streaks I just stop playing for the day, sometimes I can be only 30 mins in, I'll feel like bad beats are too often every hand, I end up closing and resting
So yes it very much varies how free I am and how I'm feeling that particular day to play