What Is The Leap Day? February 29

What is the leap day, February 29, which comes only once every four years?

In the solar calendar, a year deserves 365.2422 days.

However, if you set it to exactly 365 days, an error will gradually occur.

So it was corrected by setting a leap year (366 days) only once every four years, but it is not perfect either.

Therefore, in 1582, Pope Gregory XIII devised a way of ”skipping leap years only three times in 400 years.”

This is called the “Gregorian calendar” and is used in most parts of the world.

・References
– Time and Date: Leap Day Customs & Traditions