From April 30 to November 1, 1939, and from May 11 to October 28, 1940, GG trains were extended via the temporary IND World's Fair Line to World's Fair Station at Horace Harding Boulevard at all times during the 1939-1940 World's Fair. Trains were marked as S Special. The fair closed on October 28, 1940, with the station and line being demolished later that year. As a result, GG service was truncated to Forest Hills–71st Avenue. Additional GG service was provided for the 1964 New York World's Fair, running nonstop between Roosevelt Avenue and Hoyt–Schermerhorn Streets station every 30 minutes between 10 a.m. and 3:30 p.m. It took 23 minutes for trains to travel between the two stations.