On what date in 1945 was Japan's surrender formally signed?

Japan's surrender was formally signed on September 2, 1945.

The ceremony took place aboard the USS Missouri in Tokyo Bay, where Japanese representatives signed the Japanese Instrument of Surrender before Allied representatives. The document ended the state of war between Japan and the Allied powers and marked the formal conclusion of World War II.

This date is sometimes confused with August 15, when Emperor Hirohito's recorded radio address announced that Japan had accepted the Potsdam Declaration. August 15 is commonly called V-J Day in several countries, while September 2 is the date of the legal signing and is also known as Victory over Japan Day.

The ceremony began shortly after 9:00 a.m. Japan Standard Time and lasted about 23 minutes. General Douglas MacArthur signed for the Allied powers, followed by representatives of the United States, China, the United Kingdom, the Soviet Union, Australia, Canada, France, the Netherlands, and New Zealand.