The “V” in V-J Day stands for “Victory,” meaning Victory over Japan Day.
The expression followed the earlier term V-E Day, or Victory in Europe Day, which marked Nazi Germany's surrender in May 1945. V-J Day referred to the Allied victory over Japan and the end of the Second World War in the Pacific. The phrase appeared in headlines and public celebrations when Japan's surrender was announced.
The date associated with V-J Day varies by country and by whether the announcement or the formal signing is being emphasized. Emperor Hirohito announced Japan's acceptance of the Allied terms on August 15 in Japan. The formal surrender document was signed aboard USS Missouri on September 2.
In the United States, celebrations often began on August 14 because Japan's announcement arrived during the evening in U.S. time zones. Many Commonwealth countries traditionally marked August 15. These differences explain why historical references may use more than one date without describing different surrenders.