We don’t want to jinx it, but it seems increasingly likely that we could see the end of marijuana prohibition in our lifetime. That’s thanks in part to progressive Ann Arbor, which has enacted some of the most lenient possession laws in the country since the ’70s — celebrated with this annual ode to the leaf. While a schedule of participating music, artists, and vendors wasn’t announced at the time of press, we can tell you is that comedian, advocate, and all-around stoner icon Tommy Chong will be in attendance to pose for photos and sign autographs. It’s sure to be a groovy time. Starts at noon, 800 block of Monroe St., Ann Arbor (two blocks south of the U-M Diag).