The formal surrender of Japan occurred on September 2, 1945 around 9 a.m. Tokyo time. The Second World War ended officially when representatives from the Empire of Japan signed the Japanese Instrument of Surrender in Tokyo Bay aboard the USS Missouri. TheJapanese Foreign Minister Shigemitsu signed for the Japanese government, and Gen. Umezu signed for the Japanese armed forces.
This day of days, in pictures:

11th Airborne Division Reconnaissance Battalion honor guards presented arms as Allied represented arrived to board destroyer Buchanan for battleship Missouri

The Japanese delegation arriving aboard USS Missouri, Tokyo Bay, Japan

The Japanese delegation arriving aboard USS Missouri, Tokyo Bay, Japan

General Douglas MacArthur speaking aboard USS Missouri, Tokyo Bay, Japan, 2 Sep 1945

MacArthur signing Japanese surrender aboard USS Missouri, 2 Sep 1945

Mamoru Shigemitsu signing the surrender instrument aboard USS Missouri

General Umezu signing the instrument of surrender, Tokyo Bay

Aerial photograph of battleship Missouri during the Tokyo Bay surrender ceremony
Admiral Conrad E. L. Helfrich signing the Japanese surrender document on behalf of the Netherlands aboard USS Missouri, 2 Sep 1945; note MacArthur next to Helfrich.

The Missouri filled with spectators for the signing of the instrument of surrender

Japanese delegation leaving USS Missouri, 2 Sep 1945

Foreign Minister Mamoru Shigemitsu and General Yoshijiro Umezu led along the deck of destroyer Lansdowne by US Army Colonel Sidney Mashbir after the surrender ceremonies

USS Missouri in Tokyo Bay, 2 Sep 1945



American aircraft fly over USS Missouri after the surrender
All images courtesy of WWII DB