Foundation and Empire.
Today is Japan's birthday. Actually 建国記念の日 (kenkoku kinen-no-hi) known as National Foundation Day dates back to 660 B.C according to the 日本書紀 or Nihon Shoki, The Chronicles of Japan.
Apparently, celebration of the story of the foundation of Japan by Emperor Jinmu stretches back into Japanese history, National Foundation Day did not become an official holiday until January 1873, when Japan switched from its lunisolar calendar to the Gregorian calendar.
All I know about the holiday is that it allowed me to have a long weekend and thus see an 18 hour Marathon of Heroes! So a fine holiday it has been indeed!