Original: Six days after the detonation over Nagasaki, on August 15, Japan announced its surrender to the Allied Powers, signing the Instrument of Surrender on September 2, officially ending the Pacific War and therefore World War II.
Simplified: Six days after the explosion over Nagasaki, on August 15, Japan announced its surrender to the Allied Powers, signing the surrender paper on September 2, officially ending the Pacific War and World War II.