The MtP market, located at Lamont Park at Mt. Pleasant Street and Lamont, runs from 9 am-1pm every Saturday until Nov. 17, while the 14th and U market is open at the same times outside the Reeves Center at 14th and U.
I'm a fan of them both, though they're a little farther than the Columbia Heights Community Marketplace on the Columbia Heights Civic Plaza (the triangle at 14/Park/Kenyon). That market opens the 12th, more on that to come!!
Which of the markets is your favorite?