I don't play every day. I generally play Tuesdays, Wednesdays, Fridays, and Saturdays. Tuesdays and Wednesdays consist of weekly Strikes and Raids. Fridays and Saturdays are Xur and Crucible days. Add to it the completion of at least the Vanguard bounties on these days and it mixes things up enough to keep it fresh I'll play less after Halo:MCC and AC:Unity release, but I'll still be playing at least on Tuesdays and Fridays, with playtime increasing once The Dark Below is released. Just don't overplay.