Traditional date for the foundation of Japan by Emperor Jimmu.

Emperor Jimmu was the legendary first emperor of Japan according to the Nihon Shoki and Kojiki. His ascension is traditionally dated as 660 BC. In Japanese mythology, he was a descendant of the sun goddess Amaterasu, through her grandson Ninigi, as well as a descendant of the storm god Susanoo. He launched a military expedition from Hyūga near the Seto Inland Sea, captured Yamato, and established this as his center of power. In modern Japan, Emperor Jimmu's legendary ascension is marked as National Foundation Day on February 11.

February 11 is the 42nd day of the year in the Gregorian calendar; 323 days remain until the end of the year.