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Traditions

what is a leap year?

Introduction to February 29th in leap years

Roughly four million people in the world were born on February 29th, the day that only comes around once every four years.

The Earth does not, unfortunately, go around the sun in exactly 365 days, in fact it’s closer to 365.2425 days. So every four years the calendar moves out of sync with the Earth’s orbit by just slightly less than one day.

History of :
When was the first leap year?
In 1582 the old Julian Calendar was off by 10 days and Pope Gregory XIII decreed that a new calendar (now called the Gregorian calendar) would come into effect.

Calculation rules
This would have 365 days for three years and an extra day (February 29th) in each year exactly divisible by 4.

Calculator adjustments
However it’s not exactly 1 day in every four years, so in every century year which should be one of the leap years, it wouldn’t be. Except where the year was exactly divisible by 400, so 1700, 1800 and 1900 were not leap years but 1600 and 2000 were leap years (as will be 2400AD).

This caused a lot of trouble, and wasn’t accepted in England and the American colonies until 1752 by which time they were 11 days out. The ignorant masses rioted demanding their 11 days back because the calendar jumped.

People who have a birthday on February 29th can be known as "Leaplings" and like to say that they are "only" a quarter of their real age, they like to be different and it’s always special when they have a "real" birthday.

Some (poorly written) computer systems won’t allow February 29th for registering wedding lists or birthday present lists, but ours does.

Wedding fact
It is customary for a woman proposing marriage to man to do so within leap years.