Why do we have leap years? How important are leap days
leap year with 29 days in February instead of 28. But why do we need this adjustment, and what would happen if we ignored it? In this article, we will explore the origin and importance of leap years, and how they help us keep track of time and seasons.
Why do we have Leap Years?
The reason we have leap years is because the Earth’s orbit around the Sun is not exactly 365 days. It takes about 365.2425 days for the Earth to complete one revolution around the Sun. This means that every year, our calendar is slightly behind the actual position of the Earth by about 6 hours. To correct this discrepancy, we add an extra day every four years, making the year 366 days long. This extra day is called a leap day, and it is added to the month of February, making it 29 days long instead of 28.
But how do we know which year is a leap year?
The rule is simple: if the year is divisible by 4, it is a leap year, unless it is also divisible by 100, in which case it is not, unless it is also divisible by 400, in which case it is. For example, 2024 is a leap year, because it is divisible by 4. But 2100 is not a leap year, because it is divisible by 100 and not by 400. However, 2000 was a leap year, because it is divisible by 400.
This rule was introduced by Pope Gregory XIII in 1582, when he reformed the Julian calendar that was used since 45 BCE. The Julian calendar had a simpler rule: every year divisible by 4 is a leap year. However, this made the calendar too long, by about 11 minutes and 14 seconds every year. Over time, this
