Leap Year – Why February Gets an Extra Day

Leap Year – Why February Gets an Extra Day

Leap Year happens every four years (most of the time.) During a Leap Year, February has one more day added to it.

Let’s find out why!

sun planet leap year orbit

One year, or one full circuit around the sun, takes a little more than 365 days. It actually takes 365.242190 days to make up one astronomical year.

It’s also called a solar year, a tropical year, or an equinoctial year. One trip around the sun is what our current calendar is based on.

That fraction of a day, the .242190 part? That is the additional 5 hours, 48 minutes, and 45 seconds it takes for a full revolution in our orbit. So, what happens to that extra almost 6 hours every year?

Well, if we didn’t add an extra day every so often, spring would end up being in September and we’d celebrate Christmas in May!

When Did Leap Year Begin?

To see how all this came to be, we need to go back…way back to the time of Julius Caesar and the Roman Empire.

 statue of julius caesar

At that time, the calendar in use was the Roman Republic calendar, and it was lunar, meaning it was based on the cycles of the moon, like the Chinese calendar of today.

The new moon marked the beginning of a month, and the months were either 29 days or 31 days long. (The early Romans believed that even numbers were bad luck.)

Julius Caesar spent some time in Egypt, during his many military campaigns. He saw how their calendar worked and decided to bring it back to Rome.

The Longest Year Ever!

In 46 BCE he introduced the Julian calendar. The seasons were so out of sync by then, in order to make the calendar fit the Earth's orbit, 46 BCE was made the longest year ever, lasting a whopping 455 days!

That sorted out most of the problems that were happening with the seasons not matching up to the calendar. There was still some tweaking left to get it straight.

The calculations were still off just a bit for how long it took for the earth to make its trip around the sun. At the time, the Greek astronomers had worked it out to 365 ¼ days. To make up the difference in the extra 6 hours, they added an extra day every four years.

Leap Year Math

One-quarter (1/4 or .25) of a 24-hour day is 6 hours. And 4 multiplied by 6 equals 24. Ta da!

Except it didn’t quite work out that way because that neat little fraction is just slightly off from the actual orbit.

Several extra leap days have been added over the centuries, but our calendar needed some math to make it fit the actual orbit.

 A Better Way To Calculate Leap Year

To fix the problem, Pope Gregory XIII asked an Italian scientist, Aloysus Lilius, to create a better system. Lilius came up with an equation to correct the problem.

The rules for Leap Years are still used today.

A leap day is added if the year can be evenly divided by 4. Unless it’s a century year, a year ending in ’00.’ If that’s the case, the year has to be evenly divisible by 400.

Following those rules, you can figure out when a Leap Year has happened and will happen again.

Pope Gregory XIII introduced the new calendar system, the Gregorian calendar, in September of 1582. It’s still off, but only by 11 seconds. And this is the same calendar that most of the world still uses today.

calendar page

Why is it called a Leap Year?

In non-leap years, the days move forward by one. So, if your birthday is on a Tuesday this year, the next year it’ll be on a Wednesday.

When Leap Year happens, everything after February 29th skips, or “leaps,” two days until the following February 28th.

You can find lots of Leap Day activities involving frogs, kangaroos, dolphins, and lemurs...all animals that leap!

Fun facts about February and Leap Days:

📅 February used to be the last month of the year. And, instead of adding a day at the end of the month, the 23rd of February would happen twice.

📅 People born on February 29th are called “leaplings” or “leapers.” And most of them don’t celebrate their birthdays once every four years. The majority choose to celebrate on the last day of February or the first day of March… Or they celebrate on both days!

📅 The twin cities of Anthony, Texas, and Anthony, New Mexico hold a four-day leap year festival which includes a huge birthday party for all Leap Year Babies. They are the self-proclaimed “Leap Day capitals.”


There aren’t any specific foods that are served on a Leap Day. But that doesn’t mean that you can’t start your own tradition!

Explore the many flavors from all around the world with an awesome eat2explore box and make Leap Day a special day for you!

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