I usually only play for around 1-2 hours at a time but spread out throughout different time periods. This has only been because I haven't been feeling to well. Before I was sick I played like 5-6 hours at a time and played much more then I do now. I'm on the way to a recovery so there should be many more hours spent once I am healed.
Well, it depends on my commitments. Some days will be less, and sometimes it could be more. If I don't have work and my schedule is looking free, I'd probably spend 6+ hours gaming compared to 1-2 normally.
In recent times I have been gaming a lot more, just as a way to escape life and the busy world that is happening around me. It is hard to guess how long I spend each day as it can vary and I do not look at the time often when I am going, so the time just flies by. If I had to guess though I would say around 2-3 hours each day.