I play anywhere from about fifteen minutes to several hours a day most days of the week (excluding some weekdays). On weekdays, I generally play before I fall asleep, so it depends on what time I get to bed/how tired I am/when I have to get up the next morning. The bulk of my playtime comes from weekends--I often get 4-5 hours in on weekend evenings (or at least one evening per weekend, depending on how much other work I need to get done).
When I first got the games, I played X for about 8-10 hours straight or so. I haven't had time to play that much at a stretch again, but I think I have about 55 hours on X right now or so. I also bought Y, but I haven't had time to start that yet.