Comcast (NASDAQ:CMCSA) has noted some shifts in its subscribers' video viewing habits based on data from the MSO's Xfinity TV App, both in terms of streaming video and downloaded content.Since Comcast added download capability to the Xfinity TV App in December 2012, the MSO has noted that its customers are most frequently downloading shows and films on Saturdays and Sundays, the same days they're using the record function most on the app. This suggests that subs are downloading content on the weekends to view during the coming week.In day-to-day viewing, Comcast subs still watch primetime TV, but they are increasingly watching content on mobile devices at 8 p.m., the usage peak time for the tune-in functionality of the app. A second peak appears at 10 p.m., when usage for the app tops out.