In the United States, V-J Day is commonly dated August 14, 1945.
President Harry S. Truman announced Japan’s acceptance of the Allied surrender terms on August 14 in Washington, D.C. Because of the time difference, it was already August 15 in Japan, when Emperor Hirohito’s surrender broadcast was heard by the Japanese public. This explains why August 15 is also called V-J Day in many countries, especially in Asia and Europe.
The announcement followed Japan’s destruction by atomic bombs at Hiroshima and Nagasaki, the Soviet declaration of war, and intense internal debate within the Japanese government. Japan’s formal legal surrender came later, on September 2, 1945, when representatives signed the Japanese Instrument of Surrender aboard USS Missouri in Tokyo Bay.
A common mix-up is treating the announcement date and the formal signing date as identical. They were separate events: August 14–15 marked the public announcement, while September 2 completed the official surrender ceremony.