At what Japan Standard Time did the Japanese Instrument of Surrender take effect?

The Japanese Instrument of Surrender took effect at 9:25 a.m. Japan Standard Time on September 2, 1945.

The ceremony began shortly after 9 a.m. aboard USS Missouri in Tokyo Bay. Japanese representatives signed first, followed by MacArthur and the Allied national representatives. The signing concluded at approximately 9:25 a.m., when the instrument became effective.

This precise time differs from several other important times associated with Japan’s surrender. MacArthur opened the ceremony at about 9:02 a.m., and Emperor Hirohito’s radio announcement was broadcast at noon on August 15 in Japan. The atomic bombing of Hiroshima occurred at 8:15 a.m. on August 6, but that was a separate wartime event.

The ceremony lasted only about 23 minutes, yet its legal and military consequences were enormous. Once the instrument took effect, Japanese forces were required to cease hostilities and surrender according to Allied instructions. Formal occupation and disarmament operations then proceeded across Japan and its former territories.