Emperor Hirohito’s surrender broadcast reached Japanese listeners six days after the Nagasaki bombing. Nagasaki was bombed on August 9, 1945, and the Gyokuon-hōsō aired at noon on August 15.
The interval included Japan’s cabinet crisis, the Soviet declaration of war, discussions over the Potsdam terms and a decisive imperial conference. Japanese leaders debated whether the emperor could remain on the throne under an Allied occupation. Hirohito intervened when the Supreme War Council was deadlocked.
The six-day count refers to calendar dates, not a full 144-hour interval from the exact bombing time. Japan’s acceptance message had already been transmitted to the Allies on August 10, but the public did not hear the emperor until August 15. The formal surrender ceremony followed on September 2.