When did the Japanese Instrument of Surrender take effect?

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

The document was signed aboard USS Missouri in Tokyo Bay during a ceremony that began at 9:02 a.m. The final effective time came after Japanese and Allied representatives had completed their signatures and General Douglas MacArthur closed the proceedings.

This precise time is distinct from the opening of the ceremony. It is also distinct from 15 August, when Emperor Hirohito announced Japan’s acceptance of the Allied terms in a radio address. Those earlier events signaled surrender, but the instrument’s effective time marked the formal legal end of hostilities.

The document was signed by representatives of Japan and nine Allied nations. Its provisions formalized Japan’s capitulation and placed its armed forces under the authority of the Allied powers.