It’s Leap Day! Here’s the history behind it

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It’s Leap Day! Here’s the history behind it

Every four years, an extra day is added to the calendar in order to synchronize it with the solar year.

It takes the earth 365.242 days to orbit the Sun. For this reason, the full day is only added once every four years.

The extra day, called leap day or intercalary day, is added at the end of February, giving it 29 days instead of 28.

Leap year occurs in every year that is divisible by four and only in century years that are evenly divided by 400. For example, 800, 1200, 2000 were leap years but 1700 and 1900 were not because they are not divisible by 400, even though they are divisible by four.

The practice of adding the extra day began with the creation of the Julian calendar and a decree by Julius Caesar in the year 46 B.C. The Julian calendar creates an extra day every four years, and does not follow the century-divisible-by-400 rule so there is still an 11-minute, 14-second discrepancy each year.

The 11-minute discrepancy in the Julian calendar had added up to ten days by the year 1582 A.D. so Pope Gregory XIII created the Gregorian calendar and dropped ten days from the month of October. He also established February 29 as the official date to add during a leap year, coined the term leap year, and created the rules for adding the leap year.

Currently the solar year is approximately 26 seconds shorter than the Gregorian year.
In the U.S., leap year coincides with presidential election years.
 

Source

Cable News Network

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Did You Know This Is A Leap Year?

Rotwild im Winter
Leap Day: February 29, 2016

A Leap Day, February 29, is added to the calendar during leap years. This extra day makes the year 366 days long – not 365 days, like a common year.

On February 29th, women can ask a man to marry her.

Role reversal on leap day.

When Is the Next Leap Day?
2016 is a leap year, so the next leap day is February 29, 2016.

The last Leap Day was on February 29, 2012.

Why Add a Leap Day?
Leap days are needed to keep our calendar in alignment with the Earth’s revolutions around the Sun.
It takes the Earth approximately 365.242189 days – or 365 days, 5 hours, 48 minutes, and 45 seconds – to circle once around the Sun. This called a tropical year.

Without an extra – or intercalary – day on February 29 nearly every four years, we would lose almost six hours every year. After only 100 years, our calendar would be off by approximately 24 days in relation to fixed seasonal days days like the vernal equinox or winter solstice.

Caesar Introduced Leap Years
Roman general Julius Caesar implemented the first leap day in his Julian Calendar, which he introduced in 45 BCE (Before Common Era). A leap day was added every four years. At the time, leap day was February 24, and February was the last month of the year.

Too Many Leap Years
However, adding a leap day every four years was too often and eventually, in 1582, Pope Gregory XIII introduced the Gregorian Calendar. This calendar, which we still use today, has a more precise formula for calculating of leap years, also known as bissextile years.

USA 1752: Why Are Some Days Missing?

Traditions & Folklore

Leap day as a concept has existed for more than 2000 years, and is still associated with age-old customs, folklore and superstition. One of the most well-known traditions is that women propose to their boyfriends, instead of the other way around.

What’s a Leap Second?

Leap Months

The ancient Roman Calendar added an extra month every few years to maintain the correct seasonal changes, similar to the Chinese leap month.

 

Source:
timeanddate.com