This article first appeared in the St. Louis Beacon, Feb. 28, 2012 - Debbie and Mike O’Neil will be heading off to Hawaii soon. For a couple about to celebrate their 20th wedding anniversary, it’s hardly an unusual move.
Though it is a somewhat unusual 20th anniversary.
“Twentieth or fifth — depending on whichever way you want to look at it,” chuckles Debbie O’Neil.
The O’Neils can look at it either way because the St. Louis County couple was married Feb. 29, 1992. Having such a memorable event fall on the notable date has had its share of consequences, as well as miscommunications, beginning on their first anniversary.
“I was ready to celebrate March 1 but he was ready to celebrate on the last day of February,” she said. “We’ve got our stories straight now.”
Getting the O’Neils’ story straight was much easier than getting the calendar itself straight. The roots of the couple’s odd anniversary can be traced back some two millennia to Julius Caesar. The famous Roman emperor is credited with introducing the extra day to the Western world with the Julian calendar that bears his name.
The difficulty that created Leap Year arises from the fact that while days are measured by the spinning of the Earth on its axis, years are measured quite differently. Professor George Pepe, chair of the classics department at Washington University, said many early timekeeping systems were based on the moon, such as the Islamic and Hebrew calendars.
“A lot of early calendars were tied to it because it’s much easier to see the moon and its phases,” he said.
There are drawbacks to such methodologies however. The waxing and waning of the moon does not line up with the earth’s annual swing around the sun, quickly causing the seasons to fall out of alignment with the lunar months. Some systems, like the Jewish calendar, account for this by adding an occasional leap month to keep the seasons in approximate alignment. But Caesar decided on a different tact. He moved his empire to a solar calendar, an idea he probably picked up from the Egyptians.
Still, this doesn’t completely solve the seasonal alignment issue since the number of rotations of the Earth won’t create a round figure when matched with its annual trip around the star. That annual journey comes to an unsatisfying total of 365 and one-quarter days. Hence the need for a quadrennial kick to artificially fill out the lagging calendar. Leap day was born.
Unfortunately, like so many children, it wasn’t much better at math than its parent, which is why most places don’t use the old Julian dating system any longer. Rich Heuermann, manager of the Washington University Earth and Planetary Sciences Outreach Program for the NASA Missouri Space Grant Consortium, said the “real” year isn’t 365 and one-fourth days but the somewhat less easy to remember 365.242 days — and some change.
“That means if you do the math it’s short a quarter of a day by about 11 and a quarter minutes per year,” he said.
All those 11 minute intervals began to add up over the centuries and by the late 1500s the Catholic Church, which wanted a firmer time at which to celebrate Easter, was faced with a real problem. The solution was today’s Gregorian calendar. Named for Pope Gregory XIII, the new method of marking time meant, among other things, that Leap Year really isn’t every four years. Though most people don’t know it, the extra day is dropped from years at the turn of each century unless that century is divisible by 400. That’s why 1800 and 1900 lacked Leap Days but 2000 had one.
Heuermann said that the final system, while not perfect, keeps the calendar in sync with the changing of the seasons to a remarkable degree of accuracy. We can expect to be only about a single day off over the next few thousand years.
“We don’t even know if civilization is going to hang around long enough to keep track of that,” he said.
Man of Steel is a leapling
The O’Neils aren’t the only ones who have Feb. 29 as an important date. Raenell Dawn of Keizer, Oregon feels it’s pretty important as well. Unlike them, she may not have chosen it but as a leapling, someone born on leap day, she seems anything but unhappy with her notable birthday.
“It really is a cool day,” said Dawn, co-founder of the Honor Society of Leap Year Day Babies. “It keeps the calendar in balance with the seasons. That’s pretty awesome.”
The honor society’s website, leapyearday.com, is home to a “LeapZeum” of memorabilia related to the special day including a tidbit about Superman’s 50th birthday which, as Time Magazine has noted, was rumored to be on Feb. 29.
The Man of Steel is joined by a few notable births on that day from rapper Ja Rule to singer Dinah Shore. St. Louis Cardinals’ legend, Pepper Martin, was also born on Feb. 29. Sir James Milne Wilson, a 19th century premier of Tasmania, managed to both be born and pass away on the unusual date according to a parliamentary biography.
Leaplings experience their share of annoyances. Dawn said that computer systems sometimes aren’t set up to accept her birthday, instead spitting back an “invalid date” message. Some departments of motor vehicles even change the date to Feb. 28 or March 1 in order to simplify things, she said.
“The more people we met in the club, the more we realized that it’s not just that we share the same stories growing up,” she said of the organization, which now has more than 10,000 members. “We share the same complaints as well.”
Dawn said those complaints start early with doctors encouraging Leap Day mothers to shift their babies’ birth dates forward or backward.
“They’ll say ‘You don’t want to put your kid through all that Feb. 29 stuff,’” she said. “‘It’s not really a day.’”
Those that do retain their original birthdays often have to deal with queries from well-meaning friends and strangers who all too often think clever quips like “What’s it like to be so young?” are new jokes to them.
They aren’t, of course.
“Some of us get sick and tired of the questions and some of us really don’t care,” said Dawn.
In the end, she hopes everyone will embrace Leap Day as their own.
“It’s not just our birthday,” she said. “It’s everyone’s extra day and they should do something good with it.”
Whole lotta leapin’
Leap Day won’t be the only extra unit of time added to our calendar this year. Courtesy of the International Earth Rotation and Reference Systems Service (IERS), 2012 will also be lengthened by a leap second. The tiny calendar shift is caused by an equally tiny shift in something a great deal larger.
“As the Earth spins on its axis, it spins faster than the moon goes around the Earth,” explained Erika Gibb, assistant professor in the department of physics and astronomy at the University of Missouri-St. Louis. “The tides get a little ahead of the moon and the moon’s gravity pulls them back and that creates a little friction that slows the Earth down gradually over time.”
That means two things. First, the moon is gradually moving ever so slightly away from the Earth and second, the 24-hour day is changing very, very slowly. If you’ve ever said that today felt like the longest day of your life, you were right. It was. And this one is longer still, though the change amounts to only a few microseconds a year.
Other things can also affect the process including large earthquakes which may speed the planet’s spin a bit, though not enough to counter the effects of the overall slowdown.
Leap seconds have been added a number of times over the years although there is no precise formula for their irregular appearance. Gibb said the last one was in 2008. Previous additions came in 2005 and 1998.
Meanwhile, there’s been some debate over whether to abolish the leap second altogether. According to a January BBC article, France, Germany and the United States want it eliminated while China, Canada and the United Kingdom hope it will stay.
Whatever its fate, Gibb said most of us will have to wait a long time before we’ll notice the difference.
“It takes awhile,” she said. “We only add a second every few years.”