The official V-J Day in the United Kingdom was 15 August 1945.
That date marked the public announcement that Japan had accepted the Allied terms of surrender. Emperor Hirohito’s recorded radio address was broadcast in Japan at noon on 15 August, although the recording had been made earlier.
V-J Day can refer to more than one date. In the United States and much of the Americas, the announcement was heard on 14 August because of time-zone differences. The formal surrender document was signed later, on 2 September 1945.
The United Kingdom uses 15 August for its official commemoration because it follows the date of the emperor’s announcement rather than the date of the ceremony aboard USS Missouri. Japan also observes 15 August as a national day of remembrance, though its official governmental name differs from “V-J Day.”