Why Do We Have Leap Years?

The video explores the history and evolution of calendars, starting from the need to track seasons for agriculture. It discusses the challenges posed by Earth's orbit and rotation, leading to the development of various calendar systems. The video highlights the Roman calendar reforms by Julius Caesar, resulting in the Julian calendar, and later the Gregorian calendar introduced by Pope Gregory XIII to correct inaccuracies. The Gregorian calendar, with its leap year rules, is still in use today, though it remains slightly imperfect.

What new insight or understanding did you gain from this video?