Japan notified the Allies that it accepted the Potsdam Declaration’s surrender terms on August 10, 1945.
The decision came after the atomic bombing of Hiroshima, the Soviet declaration of war, and the bombing of Nagasaki. Japan’s government communicated its acceptance through diplomatic channels, but attached a condition concerning the status of Emperor Hirohito.
The Allies replied that the emperor and Japanese government would be subject to the authority of the Supreme Commander for the Allied Powers. Japanese leaders continued debating the response, and the final decision was not announced publicly until Hirohito’s radio address on August 15.
This date is easy to confuse with other milestones. Hiroshima was bombed on August 6, Nagasaki on August 9, the public surrender announcement came on August 15, and the formal signing occurred on September 2. August 10 therefore marks Japan’s initial diplomatic acceptance, not the public announcement or the signing ceremony.