What date did the Japanese Instrument of Surrender take effect in Tokyo Bay?

The Japanese Instrument of Surrender took effect in Tokyo Bay on 2 September 1945.

Japanese and Allied representatives signed the document aboard the USS Missouri shortly after 9 a.m. Japan Standard Time. The signing concluded at about 9:25 a.m., when the formal hostilities of World War II ended. The ceremony was witnessed by representatives of the principal Allied powers and broadcast around the world.

The effective date differs from the earlier announcement dates. Japan accepted the Potsdam Declaration through diplomatic communications in August, and Hirohito’s recorded message was broadcast on 15 August. The written instrument completed the legal and military surrender process on 2 September.

The date is also associated with the official American commemoration of V-J Day. A separate peace treaty was signed at San Francisco in 1951 and entered into force in 1952, so the surrender ceremony and the later formal peace settlement should not be treated as the same event.