On what date did Japan formally surrender in the Japanese Instrument of Surrender ceremony?

Japan formally surrendered on 2 September 1945, when its representatives signed the Japanese Instrument of Surrender.

The ceremony took place aboard the USS Missouri in Tokyo Bay. Foreign Minister Mamoru Shigemitsu signed for the Japanese government, followed by General Yoshijiro Umezu, who represented Imperial General Headquarters. Allied representatives then added their signatures.

Japan had announced its decision to accept the Allied terms on 15 August, the date commonly associated with V-J Day in many countries. That announcement ended major combat, but it was not the same as the formal legal ceremony. The signing on 2 September completed the capitulation process and is generally regarded as the official end of World War II.

The ceremony began shortly after 9 a.m. Japan Standard Time and lasted 23 minutes. The document stated that Japan accepted the provisions of the Potsdam Declaration and surrendered unconditionally to the Allied powers.