How often is a leap year

Leap years keep our calendars in check! Allow us to explain why leap years are necessary and share some of the fun folklore surrounding them. 

What Is a Leap Year?

Simply put, a leap year is a year with an extra day—February 29—which is added nearly every four years to the calendar year.

Why Are Leap Years Necessary?

Adding an extra day every four years keeps our calendar aligned correctly with the astronomical seasons, since a year according to the Gregorian calendar (365 days) and a year according to Earth’s orbit around the Sun (approximately 365.25 days) are not the exact same length of time. Without this extra day, our calendar and the seasons would gradually get out of sync. (Keep reading for a longer explanation.) 

Because of this extra day, a leap year has 366 days instead of 365. Additionally, a leap year does not end and begin on the same day of the week, as a non–leap year does.

How Do You Know If It’s a Leap Year?

Generally, a leap year happens every four years, which, thankfully, is a fairly simple pattern to remember. However, there is a little more to it than that.

Here are the rules of leap years:

1. A year may be a leap year if it is evenly divisible by 4.
2. Years that are divisible by 100 (century years such as 1900 or 2000) cannot be leap years unless they are also divisible by 400. (For this reason, the years 1700, 1800, and 1900 were not leap years, but the years 1600 and 2000 were.)

If a year satisfies both the rules above, then it is a leap year. 

When Is the Next Leap Year?

Why Do We Need Leap Years?

The short explanation for why we need leap years is that our calendar needs to stay aligned with the astronomical seasons.

One orbit of Earth around the Sun takes approximately 365.25 days—a little more than our Gregorian calendar’s nice, round number of 365. Because the calendar does not account for the extra quarter of a day that the Earth requires to complete its orbit around the Sun, it doesn’t completely align with the solar year. 

Because of this .25 difference, our calendar gradually gets out of sync with the seasons. Adding an extra day, aka a “leap day,” to the calendar every 4 years brings the calendar in line and therefore realigns it with the seasons.

Without leap days, the calendar would be off by 5 hours, 48 minutes, and 45 seconds more each year.

After 100 years, the seasons would be off by 25 days! Eventually, the months we call February and March would feel like summer months in the Northern Hemisphere.

The extra leap day adjusts this drift, but it’s not a perfect match: Adding a leap day every four years overcompensates by a few extra seconds each leap year, adding up to about three extra days every 10,000 years. 

What Is a Leap Day? And a Leapling?

A “leap day” is the extra day in the leap year: February 29.

A “leapling” is a person born on a leap day. Any leap day babies out there? We’d love to hear from you in the comments below!

Leap Year Facts and Folklore

• Ages ago, Leap Day was known as “Ladies Day” or “Ladies’ Privilege,” as it was the one day when women were free to propose to men. Today, Sadie Hawkins Day sometimes applies to Feb 29 (leap day), based on this older tradition.
• According to folklore, in a leap year, the weather always changes on Friday.
• “Leap year was ne’er a good sheep year” (old proverb)

Are Leap Years Bad Luck?

Many feel that to be born on Leap Day, thereby becoming a “leapling,” is a sign of good luck.

In some cultures, it is considered bad luck to get married during a leap year.

We don’t know of any evidence supporting that marriage theory, but we do know that during leap years:

• Rome burned (64),
• and the Titanic sank (1912).

By the same token, also in leap years:

• the Pilgrims landed at Plymouth, Massachusetts (1620),
• Benjamin Franklin proved that lightning is electricity (1752),
• and gold was discovered in California (1848).

Do you have any leap year memories? Are you a Leapling yourself? Please share in the comments below!

The year 2021 is not a leap year, meaning there are 365 days in the annual calendar this time around, but the next one isn't far off – here’s when

As the end of February approaches, many are wondering when the next leap year is and how often they occur.

Leap years tend to take place every four years, leading many to search for answers to a host of questions about them, and their origins.

This year - 2021 - is not a leap year, meaning there are 365 days in the annual calendar this time around, but the next one isn't far off.

When was the last one, when is the next one, and why do we have them at all? Read on to discover all there is to know about leap years.

What is a leap year?

A leap year is a year in which an extra day - 29 February - is added to our annual calendars.

The 29 February is known as Leap Day and anyone born on this day is generally referred to as a Leapling.

Leap years occur every four years.

Why do we have a leap year?

Broadly speaking, leap years happen every four years to keep our calendars in sync with the seasons.

There are 365 days in the Gregorian calendar - used in most parts of the world, including the UK - but it takes the Earth a little longer to complete a full orbit of the Sun.

A full orbit of the Sun takes 365.25 days so an extra day is added to the calendar every four years to correctly align the solar year with the astronomical seasons.

If the day was not added then the calendar would be out of sync by five hours, 48 minutes and 45 seconds each year, which could have a big impact over time.

It could see a big shift in the seasons as we know them, as they move a day every four years, which could lead to winters in June and July and summers in November and December months.

How many days are in a leap year?

There are 366 days in a leap year - one more than the usual 365 days.

When was the last leap year?

The last leap year was in 2020. On 29 February 2020, South Korea reported 3,150 confirmed cases of coronavirus, as the outbreak began its grip across the world.

When is the next leap year?

The next leap year will take place in 2024. The next Leap Day will be Thursday 29 February 2024.

After that, leap years will take place in 2028, 2032, 2036, and 2040.

Leap year folklore

People born on the 29 February believe it to be a sign of good luck - though can only celebrate their official birthdays every four years - which might not be as much fun as being born on either the 28 February or 1 March.

Leap Day was also known to be a time when women were able to propose to men, rather than the other way round, though this tradition has fizzled out in more recent years.

It is considered bad luck to get married during a leap year in Greece. Superstition says that couples that tie the knot in a leap year are more likely to get divorced.

In Scotland, leap years are regarded as bad years for livestock after an old saying "leap year was ne'er a good sheep year". Though its origins are not clear, Scottish farmers tend to take extra care on 29 February.

Is 2022 a leap year?

Is a leap year every 7 years?

Why do we have 29 days in February every 4 years?

Do leap years always happen every 4 years?