That's the date mentioned on the MVSNA listserv. For you new people this is what usually happens. The church has a parade. A big parade. A long parade that crosses Rhode Island, snarling traffic. I think last year they went up to Florida Avenue. Also last year, they worked with the city. As opposed to previous years where deacons and other church people blocked streets and directed traffic.
It is interesting and it brings in a lot of United House of Prayer folks.