The Japanese Instrument of Surrender took effect at 9:25 a.m. Tokyo time on 2 September 1945. The document was signed aboard USS Missouri in Tokyo Bay during a ceremony that began shortly after 9 a.m.
The time is distinct from the time of individual signatures. Mamoru Shigemitsu signed first at about 9:04 a.m., and Douglas MacArthur signed shortly afterward. The ceremony concluded at approximately 9:25 a.m., when the instrument became effective and hostilities with the Allied powers were formally ended.
This timing helps explain why accounts sometimes give different times for Japan’s surrender. Emperor Hirohito’s radio broadcast announcing acceptance of the Allied terms occurred on 15 August, while the written surrender became effective on 2 September. V-J Day has consequently been associated with both dates in different countries and contexts, but the formal instrument’s effective time belongs specifically to the September ceremony.