When did the Allied occupation of Japan begin after the surrender announcement?

The Allied occupation of Japan began on 28 August 1945.

Japan announced its surrender on 15 August, but occupation operations did not begin immediately. Allied forces first made arrangements for landings, communications, demobilization, and the transfer of authority from the Japanese government and military.

On 28 August, occupation forces began entering Japan under the command of General Douglas MacArthur, the Supreme Commander for the Allied Powers. The formal surrender ceremony followed on 2 September aboard USS Missouri in Tokyo Bay.

The occupation lasted until the Treaty of San Francisco came into force on 28 April 1952, although the United States retained control of Okinawa for longer. The start of the occupation should therefore not be confused with either the surrender broadcast or the formal signing date.