Japan's Instrument of Surrender officially took effect at 9:25 a.m. Tokyo time on September 2, 1945.
The ceremony aboard USS Missouri began at approximately 9:02 a.m. in Tokyo Bay. Japanese Foreign Minister Mamoru Shigemitsu signed first at about 9:04, followed by General Yoshijiro Umezu. Allied representatives then signed the document, and the instrument became effective at 9:25 a.m.
The precise time helps distinguish several milestones that are often blended together. Emperor Hirohito's surrender broadcast had aired in Japan at noon on August 15. The formal signing began at 9:02 a.m. on September 2, while 9:25 a.m. marked the document's effective time. The entire public ceremony lasted roughly 23 minutes.
The legal effect extended beyond the ship's deck. Japan accepted the Potsdam Declaration, ordered its armed forces to cease hostilities, and agreed to surrender its arms. Separate regional surrender ceremonies followed, including in the Philippines, Korea, and Southeast Asia. Thus, the time records the completion of the formal instrument rather than the moment when the Japanese public first learned of the decision.