In the United States, V-J Day was observed on August 14, 1945, after President Harry Truman announced Japan’s surrender.
The announcement followed Japan’s acceptance of the Allied terms and came through a presidential radio address. Newspapers and public celebrations quickly spread the news across the United States, where the date was still August 14 because of the time difference with Japan.
The date can be confusing because August 15 was already the next day in Japan when Emperor Hirohito’s surrender broadcast was heard there. September 2 is another important date: it was when Japanese representatives formally signed the surrender instrument aboard USS Missouri in Tokyo Bay.
Thus, August 14 is the traditional American V-J Day date, while August 15 is commonly used in Japan and some other countries for the announcement of the surrender.