I have been on klonopin (clonazepam) 2mg once a day for a year how long will it take to go clear for a drug screen for work stopped taking two days ago?

Varies widely. The range for 1/2-life (i.e., 1mg still there) is 18-50 hrs! People metabolize differently. So, it could be over 4 full days! But if you have a legit Rx - it should be honored. Try not to worry if you are being a responsible adult. If you're not..... Well, by 35 perhaps you need to start moving in that direction. Best!