At what time did Hirohito's surrender broadcast begin in Japan in 1945?

Hirohito's surrender broadcast began at noon Japan Standard Time on August 15, 1945.

The recorded message was transmitted by NHK, Japan's national broadcaster, and was introduced as an announcement of the highest importance. Listeners heard the national anthem before Hirohito's voice, followed by an explanation of the message's meaning.

The timing matters because the recording itself was made the previous night, after officials prepared the imperial rescript. A military coup attempt tried to prevent the recording from being broadcast, but the discs were hidden and safely delivered to the broadcasting station. The broadcast therefore reached the public at noon despite the attempted intervention.