It's nearly 7 months for me as a completely plant based athlete. During this time, I've been working out hard, 5 days a week and have been seeing results. It may not be as fast as I like, but I do see progress each week.
I never would have believed years ago that muscle building could be possible without meat. After all, nearly everyone I encounter eats animal products, and some use whey protein powder. But I discovered there are many athletes out there proving that "No Meat is No Problem"... people like Robert Cheeke, the first vegan bodybuilder that I read about.