National Geographic
National Geographic: 45 Bce: Julius Caesar Takes a Leap
Why do we have an extra day at the end of February every four years? We have Julius Caesar to thank! Read this short explanation about how the calendar kept falling out of step with the seasons and Caesar's solution to the problem.
Mocomi & Anibrain Digital Technologies
Mocomi: What Is Leap Year?
Learn when and why we have leap years.