The anticipated 1940 Summer Olympics , which were to be officially known as Games of the XII Olympiad and originally scheduled to be celebrated between September 21 and October 6 1940 in Tokyo , Empire of Japan , were canceled because of World War II . The anticipated 1940 Summer Olympics , officially known as the Games of the XII Olympiad and originally scheduled to be held from September 21 to October 6 , 1940 , in Tokyo , Japan , were canceled due to the outbreak of World War II .