Spaceship Earth
An educational series explaining the operation of the solar system using 3D animation. Its 52 episodes provide a week-by-week description of the operation of the solar system.
9. Week 9: The Calendar (Late February)
0.0May 18, 1997 · 5 min
Leap Days: The Earth misses a quarter of a day. Gregorian and Orthodox calendars. Solar and lunar calendars. Solid and gaseous planets.