The initial surrender was announced on August 14, 1945 - in Japan it was August 15, 1945. The formal surrender came a short time later on September 2, 1945. Japanese citizens refer to the day as Shusen-kinenbi. In literal translation it means "memorial day for the end of the war."
The announcement by Emperor Hirohito that Japan was surrendering came over the airwaves at noon on August 15, 1945. The Japanese had accepted the Potsdam Declaration. This document outlined the terms of surrender by the Japanese armed forces. If the Japanese had not accepted the terms, it was said that they would face "prompt and utter destruction." President Harry S. Truman declared September 2 - VJ Day - on the same day that Japan formally signed the surrender agreement. The signing took place in Tokyo Bay aboard the USS Missouri battleship.