At what time was the war officially declared over during Japan's surrender ceremony?

The war was officially declared over at 9:25 a.m. Japan Standard Time during Japan's surrender ceremony.

The Japanese Instrument of Surrender was signed aboard USS Missouri in Tokyo Bay on 2 September 1945. The ceremony began shortly after 9 a.m., and the signatures were completed in sequence: Japanese representatives signed first, followed by MacArthur and representatives of the Allied nations.

At 9:25 a.m. JST, the ceremony concluded and the war was officially over. This precise time is different from 9:02 a.m., when MacArthur opened the proceedings, and from noon on 15 August, when Emperor Hirohito's surrender broadcast was heard by the Japanese public.

The distinction between announcement, ceremony, and legal conclusion explains why sources cite several important times and dates. Japan's decision was announced in August, but the formal act that ended hostilities occurred in Tokyo Bay on 2 September. The ceremony lasted approximately 23 minutes.