Today is the 80th Anniversary of V-J Day in 1945, When Japan Officially Surrendered, Ending World War II

Statue of an American Soldier at the World War II Memorial in Trenton, New Jersey

http://www.history.com/this-day-in-history

Sep 2, 1945: Allies celebrate V-J Day

On this day in 1945, the USS Missouri hosts the formal surrender of the Japanese government to the Allies. Victory over Japan was celebrated back in the States.

As Japanese troops finally surrendered to Americans on the Caroline, Mariana, and Palau islands, representatives of their emperor and prime minister were preparing to formalize their capitulation. In Tokyo Bay, aboard the Navy battleship USS Missouri, the Japanese foreign minister, Mamoru Shigemitsu, and the chief of staff of the Japanese army, Yoshijiro Umezu, signed the "instrument of surrender." Representing the Allied victors was Gen. Douglas MacArthur, commander of the U.S. Army forces in the Pacific, and Adm. Chester Nimitz, commander of the U.S. Pacific Fleet, now promoted to the newest and highest Navy rank, fleet admiral. Among others in attendance was Lt. Gen. Jonathan Wainwright, who had taken command of the forces in the Philippines upon MacArthur's departure and had been recently freed from a Japanese POW camp in Manchuria.

Shigemitsu would be found guilty of war crimes and sentenced to seven years in prison subsequent to the surrender. The grand irony is that he had fought for concessions on the Japanese side in order to secure an early peace. He was paroled in 1950 and went on to become chairman of Japan's Progressive Party. MacArthur would fight him again when he was named commander in chief of the United Nations forces in Korea in 1950.

1945 Japan surrenders, bringing an end to WWII HISTORY.com Editors This Day In History: Japan surrenders, bringing an end to WWII  Published: February 09, 2010 Last Updated: May 28, 2025:

https://www.history.com/this-day-in-history/september-2/japan-surrenders

So yes, today if the 80th anniversary of V-J Day. That was the day when Japan officially surrendered (although they had, in principle, surrendered earlier). This surrender marked the official end of World War II.

Japan had arguably begun World War II well before the conflict erupted in Europe, and even before Hitler ever ascended to power in Europe. They invaded Manchuria in 1931. This conflict escalated in 1937, and became the Second Sino-Japanese War in 1937. Eventually, this became part of World War II, which is why it seems to me that World War II actually began earlier than September 1, 1939, when Hitler invaded Poland. 

Of course, these were two different theaters of war. Hitler and Nazi Germany invaded numerous countries and basically took over almost all of Europe for a while, but eventually were beaten back to the borders of the Reich and then into the capital city of Berlin. Once Berlin fell and Hitler committed suicide, it was a matter of days before the top-ranking Nazis officially surrendered on May 8, 1045, although it is celebrated on May 9, 1945 in Russia. 

It was Japan's attack on Pearl Harbor in Hawaii on December 7, 1941, which forcibly brought the United States into the conflict. The United States declared war on Japan the next day, and then Germany declared war on the United States days after that. Thus, all of the world's major powers at that point were engaged in the conflict, which was and still is the biggest war the world has ever seen. 

However, it ended on this day in 1945 with the official surrender of Japan, on what has come to be known as V-J Day.