V-J Day was first celebrated in Japan on August 15, 1945, after Emperor Hirohito announced Japan’s surrender.
The announcement followed Japan’s acceptance of the Potsdam Declaration, the Allied statement demanding the surrender of Japanese forces. Hirohito’s speech was broadcast at noon Japan Standard Time and told listeners that Japan had accepted the Allied terms.
The date can be confusing because time zones produced different calendar dates elsewhere. In the United States and much of the Western Hemisphere, the announcement was heard on August 14. The formal surrender ceremony took place later, on September 2, aboard USS Missouri in Tokyo Bay.
V-J Day therefore refers both to the public announcement and, in some contexts, to the later signing of the surrender document. In Japan, August 15 remains the date most closely associated with the end of the war, while September 2 marks the legal and ceremonial conclusion of hostilities.