I can't really say. I know there was a time that right after I met my girlfriend where I didn't play games much (like once a week at the most) and that lasted about 5 to 6 months.. it's gone back up since then though, strange considering I see her now (now my fiancee) more than ever before..
There was a slow period last year where there was the magical combination of me being too busy and being in-between games. I probably went about two days without playing anything.