On May 1, unions all over Japan celebrate May Day, the international day for workers. Workers gather together at parks and hold demonstrations and parades. May Day has its origins in a strike that occurred in the United States on May 1, 1886, a strike that called for an eight-hour workday. Japan’s first May Day event was held in Tokyo on May 2, 1920, which was attended by about ten thousand workers. There were no May Day events from 1936 to 1945 because of political conditions in Japan, but May Day events were revived in 1946. May Day in 1952, known as Bloody May Day, was unforgettable: May Day demonstrators, many of whom opposed the San Francisco Peace Treaty, clashed with police, resulting in many deaths and injuries. After World War II, the Japanese labor movement gained strength, peaking in the 1970s, after which the labor movement began to decline. May Day demonstrations have diminished as well. Many claim that May 1 is not a good day for labor demonstrations, since it falls within Golden Week, a vacation period in Japan that includes four public holidays in one week. Because of Golden Week, even union members may prefer going out with their families for leisure activities, rather than participating in May Day demonstrations.