V-J Day is the phrase used for Victory over Japan Day, marking the Allied victory over Japan in World War II.
The abbreviation “V-J” means “Victory over Japan.” It parallels V-E Day, which means Victory in Europe and marks Nazi Germany’s defeat in Europe. V-J Day is associated with the August 1945 announcement of Japan’s surrender and with the formal surrender ceremony on September 2.
Different countries and sources use different dates for V-J Day. In the United States, celebrations began after news of the surrender announcement reached the public on August 14, 1945, because of the time difference. In many other countries, August 15 is observed because that was when Hirohito’s broadcast was heard in Japan and much of the British Commonwealth.
September 2 is also called V-J Day because that was the date of the formal signing aboard USS Missouri. The varying dates reflect the difference between the announcement, the time at which news spread internationally, and the legal signing of the surrender document.
The term is historical and commemorative rather than the name of a treaty or a single ceremony.