Centuries ago, people used a calendar without leap years. Strange to think about, right? We've become so accustomed to seeing our calendar as a fact, we have to remind ourselves it is an invention. Wondering why we have leap years? Here are a handful of leaping fun facts to share with your kids:

What is a leap year?

Every four years — nearly every four years, we will get to that later — an extra day is added to our calendar. This means that during a leap year there are 366 days rather than the typical 365 days. Why? Because our calendar is based on a solar year, the amount of time needed for our planet to complete an orbit of the sun. Earth's orbit takes 365 days, but not exactly 365 days. The complete orbit takes 365 days, 5 hours, 48 minutes and 46 seconds. Although the extra 5+ hours may not seem to make much of a difference in one year, those hours add up. Eventually, hours turn into days. By introducing a leap year every four years, the calendar is adjusted so it once again is in tune with the earth's orbit of the sun. This system was introduced with the Gregorian calendar which was invented in 1582.

When is leap day?

Leap Day is February 29. The idea was to keep the earth in sync with the sun so that the vernal equinox is always close to March 21. This equinox, when the span of night and day are close to equal, marks the beginning of spring since the days that follow the spring equinox become longer and sunnier. One of the goals of the leap year in the Gregorian calendar is to keep March 21 as close to the vernal equinox as possible so the Easter holiday is always celebrated in spring.

Prior to the use of the Gregorian calendar, the Julian calendar was prominent. The Gregorian calendar was an adjustment as is subtracted 10 days from the Julian calendar and created the leap year system to stay in tune with the equinox.

What if you are born on a leap year?

People born on February 29 are sometimes referred to as leaplings or leapers. Technically, leapers only have a birthday every four years, but we know that time does not stop for anyone and usually individuals born on Leap Day opt to celebrate their birthdays on February 28 or March 1 during common years.

Those born on a Leap Day might be interested in the classic story of "The Pirates of Penzance," a Gilbert and Sullivan musical which has also been made into several movies. In Penzance, Frederic is an indentured pirate. He is scheduled to have his freedom restored on his 21st birthday. But, when his apprenticeship paperwork is examined, the truth is revealed: Fredric was born on a Leap Day, so he won't truly turn 21 until he is an old man. Of course that doesn't happen to modern-day leapers, the law is designed so individuals born on Leap Day won't have to wait as long as Frederic for stipulated age limits. If you are born on February 29, you will still be able to drive and marry and all other legal age activities in the same year as those who share your birth year.

Leap stories

As a unique day, it should come as no surprise that leap years are associated with superstitions. There have been many tales of being born on Leap Day being lucky or unlucky and in some countries, couples still shy away from getting married in a leap year, worrying the date will be unlucky for the marriage.

Likely the most cited leap year tradition is that for centuries it was the rare day women could propose marriage to men. Yes, Leap Day is the original Sadie Hawkins Day. The story goes that in the fifth century, Saint Bridget expressed dissatisfaction to Saint Patrick about women waiting for men to propose to them. She felt women should be able to ask men for their hand in marriage as well. So, Saint Patrick allowed women proposals, but only on Leap Day. That's right, there was a time when women in love had to wait a four year cycle before making a proposal.

How to celebrate leap day

Get leaping! Literally... Many with young kids use frog-themed activities to celebrate Leap Day. For example, have a family contest to see who can jump the farthest. Gather the neighborhood kids for a jump rope competition. Some also opt to use the holiday as a teaching opportunity on the science of leap year or to teach about the number four.

And once the kids get an understanding of how leap year works, you can add this additional caveat: The math is still a bit off. That's right, even with leap years the Gregorian calendar is off by 11 minutes and 14 seconds per year. To solve this, the Gregorian calendar omits leap years three times every 400 years. How is this decided? Well, one simply omits February 29 in century years not precisely divisible by 400. Want a cheat sheet? Here ya go: 2000 and 2400 are leap years, while 2100, 2200 and 2300 are not.

The leap cycle is full of math amusement, get out the calculators and a solar chart to figure it out. Or simply accept an extra day of family-filled fun. Happy Leap Day! ■

Mali Anderson is always happy to have another day to write, draw and play with her daughter, Ivy. It doesn't have to be February 29, but she'll happily take it.


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