Leap Year: An Extra Day Every Four Years!

Since 1425 students have been using a simple Mother Goose-type rhyme to keep track of how many days are in each month:

Thirty days hath September,

April, June, and November.

All the rest have thirty-one,

Then depending on where or when you grew up, the poem finishes with an exception about February:

Excepting February alone,

And that has twenty-eight days clear

And twenty-nine in each leap year.

Or

Save February at twenty-eight,

But leap year, coming once in four,

February then has one day more.

Groucho Marx famously once cracked that “my favorite poem is the one that starts ‘Thirty Days Hath September …’ because it actually means something,” and for all of us it does really mean something in 2024 as another Leap Year is upon us.

The History of Leap Year

The concept of a leap year dates to ancient civilizations who observed the mismatch between the calendar and the Earth's revolution around the sun.

A standard year has 365 days, but it takes Earth approximately 365.242190 days to complete its orbit or to put it another way: 365 days 5 hours 48 minutes, and 56 seconds. This slight difference accumulates over time, causing the seasons to drift out of sync with the calendar.

“If we didn’t account for this extra time, the seasons would begin to drift. This would be annoying if not devastating, because over a period of about 700 years our summers, which we’ve come to expect in June in the northern hemisphere, would begin to occur in December!” writes Bob Craddock in the Smithsonian.

 To address this discrepancy, the Julian calendar, introduced by Julius Caesar in 45 BC, added an extra day every four years.

However, this system overcompensated slightly, leading to another adjustment with the Gregorian calendar in 1582.

“By adding a leap day every four years, we actually make the calendar longer by over 44 minutes. Over time, these extra 44+ minutes would also cause the seasons to drift in our calendar. For this reason, not every four years is a leap year,” explains Craddock.

The new rule stipulated that years divisible by 4 are leap years, except for century years (divisible by 100) unless also divisible by 400. Thus, 1700, 1800, and 1900 were not leap years, but 2000 was.

This refined system ensures the calendar stays relatively aligned with the seasons.

Interesting Facts about Leap Year

Here are some interesting facts about leap years and leap days:

• Nothing New Under the Sun: While Julius Caesar is often credited for originating leap days, he got the idea, according to USA Today and National Geographic, from the Egyptians, which by the third century BCE followed a solar calendar that spanned 365 days with a leap year every four years.
  
  
• People born on a leap day are known as Leaplings.
  
  
• Famous leap day births include:

o   Composer Gioachino Rossini

o   Pope Paul III

o   Singer and actor Ja Rule

o   Foster the People band lead Mark Foster

o   Motivational speaker Tony Robbins

o   Prime Minister of Spain Pedro Sanchez

o   Entertainer Dinah Shore

o   Model Antonio Sabato, Jr.

o   Bandleader Jimmy Dorsey

o   Baseball player Pepper Martin

o   Hockey player Henri Richard

o   Actor Alex Rocco

o   Actor Dennis Farina

o   Soccer player and announcer Taylor Twellman

• Longshots: Your odds of being born on Feb. 29 are one-in-1,461.
• Happy Birthday to You: Some 5 million people will celebrate their birthday on Feb. 29 this year, according to the History Channel and USA Today.
• Mark Your Calendars: The next leap years are 2028, 2032 and 2036.
• Leap year babies and birthdays: Some leap year babies celebrate their birthdays on February 28th in non-leap years, while others choose March 1st.
• Win at Trivia Night: In Superman comics, Superman is born on February 29^th!
• Pop the Question: In some countries, such as Ireland, it was tradition that Feb. 29 was the only day that women could propose marriage to men. This is why some call it Bachelor’s Day.

Does Leap Year Impact Businesses and the Economy?

The economic impact of leap years is generally considered minimal. Some businesses, like retailers and event planners, might experience slight fluctuations in sales or scheduling due to the extra day.

However, these effects are usually negligible and even out over time.

“One extra day makes the year 0.27 percent longer theoretically allowing for 0.27 percent more economic activity to take place. So it’s true that all things considered you might get a smallish boost to aggregate output and income totals,” wrote Matthew Yglesias in Slate. “Taking another full 24 hours to do another 24 hours worth of work doesn’t change anything. That said, in shorter time frames it does make a difference. Anyone who’s subjected to monthly performance metrics of any kind will do a bit better than he would in a normal February.”

CFO magazine, however, says that leap year can disrupt some accounting, payroll, compliance, and other normal business functions.

“From payroll processing to financial statement preparations to budget tracking, many key business functions are dictated by the calendar. So when an extra day is introduced, intricate accounting mechanisms are thrown off balance, forcing financial teams to make rapid adjustments,” says the magazine.

CFO says to watch out for:

• Accounting: Crucial to account for the extra day in the reporting period which may require adjusting accruals, depreciation schedules, and other accounting entries to reflect the correct time period.
  
  
• Reporting and analysis: The extra day needs to be accounted for in year-over-year comparisons as well as key performance indicators. An additional day can also impact revenue projections, expense forecasts, and cash flow projections.
  
  
• Payroll and compliance: Payroll systems need to be configured to handle the extra day, including the proper calculation of withholding of payroll taxes. Employee benefits and deductions need to take into account the extra day.

Leap year primarily serves as a crucial adjustment to maintain the accuracy of our calendar system and its alignment with the natural world. It's a testament to human ingenuity in devising solutions to complex astronomical and calendrical challenges.

So, when February 29^th rolls around this year, remember the fascinating history and scientific reasoning behind this unique day. It's a reminder of our ongoing quest to understand and synchronize with the rhythms of our planet.