In the 1945 Allied victory term V-J Day, the letter J stands for Japan.
The abbreviation follows the pattern established by V-E Day, meaning Victory in Europe. V-J Day therefore means Victory over Japan, marking Japan’s defeat in World War II. Allied newspapers, governments, and military organizations used the term as news of Japan’s surrender spread in August 1945.
The date associated with V-J Day varies by country and by which event is being emphasized. Japan announced its acceptance of the Allied surrender terms on August 15, 1945, while the announcement reached the United States on August 14 because of time-zone differences. The formal surrender documents were signed on September 2, 1945.
This creates a common mix-up: V-J Day can refer either to the announcement of surrender or, especially in the United States, to the formal end-of-war ceremony. The “J” consistently refers to Japan, not to a person, military branch, or Japanese city.