At what time did Japan's surrender formally take effect aboard USS Missouri?

Japan's surrender formally took effect at 9:25 a.m. Japan Standard Time aboard USS Missouri.

The ceremony began shortly after 9 a.m. in Tokyo Bay on September 2, 1945. Mamoru Shigemitsu signed for the Japanese government at 9:04 a.m., and General Yoshijiro Umezu signed for the Imperial Japanese General Headquarters at 9:06 a.m. MacArthur signed at 9:08 a.m.

The Allied representatives then signed in sequence, including Chester Nimitz for the United States. Once the signatures were complete, MacArthur delivered closing remarks and ended the proceedings. The instrument stated the surrender conditions that brought the war's formal hostilities to an end.

The time should not be confused with noon on August 15, when Hirohito's recorded announcement was broadcast in Japan, or with 9:04 a.m., when the first Japanese signature was placed on the instrument. Those were earlier moments in the surrender process.