August 14, 1945 -- V-J Day (Victory in Japan), when the Japanese accepted the terms of the Potsdam Declaration and unconditionally surrendered. September 2, 1945 - Day the Japanese delegation formally signs the instrument of surrender on board the USS Missouri, marking the official ending of World War II. 2,194 -- Days between the German invasion of Poland on September 1, 1939, through September 2, 1945, when Japan signs the unconditional surrender.