Japan’s acceptance of the Potsdam Declaration was announced by radio in Japan on 15 August 1945.
Emperor Hirohito’s recording was broadcast to the Japanese public at noon Japan Standard Time. The address used formal court language, and many listeners found the Emperor’s voice difficult to understand because it was the first time most had heard it.
The broadcast announced acceptance of the Allied declaration, but it did not itself complete the legal surrender. Japan’s representatives still had to sign the formal Instrument of Surrender, which happened aboard USS Missouri on 2 September.
The date can cause confusion because the announcement occurred on 15 August in Japan, while it was still 14 August in parts of the United States. The phrase V-J Day therefore appears with different dates in different countries and historical contexts.