The M Queens Boulevard/Sixth Avenue Local is a rapid transit service in the B Division of the New York City Subway. Its route emblem, or "bullet", is colored since it uses the IND Sixth Avenue Line in Manhattan. The M operates at all times. Weekday rush hour, midday, and early evening service operates between 71st Avenue in Forest Hills, Queens, and Metropolitan Avenue in Middle Village, Queens, making local stops along its entire route; weekend daytime and late evening weekday service is cut back from 71st Avenue in Queens to Essex Street in the Lower East Side of Manhattan; late night service short turns at Myrtle Avenue in Brooklyn. The M is the only service that travels through the same borough via two different, unconnected lines. Additionally, the M is the only non-shuttle service that has both of its full-run terminals in the same borough (Queens). Though the full route length between 71st Avenue and Metropolitan Avenue is about , the stations are geographically located apart, marking this as the shortest geographic distance between termini for any New York City Subway service that is not a shuttle service. An MJ service ran the entire BMT Myrtle Avenue Line until 1969, when the section west of Broadway in Brooklyn was demolished. Before 2010, the full-length M ran from Middle Village to southern Brooklyn via the BMT Nassau Street Line and Montague Street Tunnel. The M had originally run on the BMT Brighton Line to Coney Island–Stillwell Avenue until 1987. Afterward, it used the BMT Fourth Avenue Line, and BMT West End Line in Brooklyn, terminating at Ninth Avenue or Bay Parkway. From July 2017 to April 2018, the full-length M terminated at Broadway Junction in Brooklyn; a limited number of M trains operated between 71st Avenue in Queens and Second Avenue in Manhattan. As part of the 14th Street Tunnel shutdown, between April 2019 and April 2020, M service was extended to 96th Street in the Upper East Side during weekday late evenings and weekends, as an alternative for train service. History M service 1914–1960 Until 1914, the only service on the Myrtle Avenue Line east of Grand Avenue was a local service between Park Row (via the Brooklyn Bridge) and Middle Village (numbered 11 in 1924). The Myrtle Viaduct, a two-track ramp connecting the Myrtle Avenue Line with the BMT Broadway Elevated (now the Jamaica) Line at the Myrtle Avenue