Hirohito’s recorded surrender speech began at noon on Japanese radio on August 15, 1945.
Japan Broadcasting Corporation, or NHK, scheduled the announcement for 12:00 p.m. Japan Standard Time. An announcer told listeners to stand for an announcement of the highest importance before the national anthem and the emperor’s recording were transmitted.
The address was unusual because it was the first known occasion on which ordinary Japanese people heard the voice of their emperor. Hirohito did not speak live; technicians had recorded the rescript inside the Imperial Palace the night before. The recording lasted only a few minutes.
The timing also helps explain differing dates reported outside Japan. Because of time-zone differences, audiences in the United States heard news of the announcement on August 14, while Japan’s broadcast occurred on August 15. The formal surrender itself still took place later, on September 2, aboard USS Missouri in Tokyo Bay.