You will know when its time to have a beer with the boys....don't worry about that right now. The important thing is you have realized you need to stay away from those triggers. We lose many a quitter to an early quit beerfest. As far as your friends go, if they are your friends they will understand. If they don't, then fuck'em.
A timeline......50 days seems to be reasonable for most guys. However, let me throw this at you. You have made the decision to quit, you are done, finished and have posted roll call for the day. No amount of beer or peer pressure can make you reverse that decision. I'm not saying go get hammered, I just want you to think about the power of choice.
Congrats on your decision.