Depends how much you smoke when you do decide to smoke again. If you burn a couple joints or more your probably gonna fail for at least a whole week, probably more. If you smoke a couple one hitter bowls or one or two regualar bowls you will probably be good by the later part of the week. Thats assuming you don't smoke a lot now, it took me 2 months to get entirely cleaned out when I had a job with drug testing because I was smoking at least a bowl or two and usually more every day.