Why is it necessary to have leap years?
Roman Dictator, Julius Caesar, who lived about 50 years BC, reformed a calendar based on 364 days, with an occasional extra leap day.
2020 is a leap year, meaning February this year has 29 days instead of the usual 28. The reason one day has to be added to the calendar every four years, is to keep the calendar in line with the earth’s movement around the sun.
While the modern calendar contains 365 days, the actual time it takes for Earth to orbit the sun is slightly longer – roughly 365.2421 days. The difference might seem negligible, but over decades and centuries that missing quarter of a day per year can add up. To ensure consistency with the true astronomical year, it is necessary to periodically add in an extra day to make up the lost time and get the calendar back in sync with the heavens.
According to History.com, the Egyptians were the first ones to figure out the need for a leap year, but it became more widespread in the reign of Julius Caesar.The 365 day calendar was finalized in 46 B.C. and included a leap day every four years. But that was not enough. Because Caesar’s calendar was running a surplus of about 11 minutes a year, which meant a full day was added every 128 years. By the 14th century, the calendar was 10 days off the solar year.
In 1582, Pope Gregory brought in the Gregorian calendar, which added this little fix. The leap year occurs every four years except for years evenly divisible by 100 and not by 400.This is the fix that has lasted to this day, although history.com warns that in 10 000 years discrepancies will need to be addressed again.
