Japan’s surrender formally took effect at approximately 9:25 a.m. Japan Standard Time on September 2, 1945.
The ceremony aboard USS Missouri began shortly after 9 a.m. in Tokyo Bay. Mamoru Shigemitsu and Yoshijiro Umezu signed for Japan, followed by General Douglas MacArthur and representatives of the Allied governments. The proceedings lasted about 23 minutes.
The exact timing distinguishes the legal conclusion of the ceremony from the broader celebrations called V-J Day. The date was September 2 in Japan, while the ceremony and its news coverage were experienced differently across international time zones.
Japan had already announced its acceptance of the Potsdam Declaration in Emperor Hirohito’s August 15 broadcast. However, the written instrument was necessary to document the capitulation and establish the formal end of hostilities with the Allied powers.