Leap Year: Getting Right with the Sun

Well, tomorrow is that odd day that pops into our calendar every four years: February 29th. Leap Year day. No, wait - it's a leap year if you can divide it by four, but it's not a leap year if you can divide it by 100, right? Um, except every 400 years. I think. What was I saying?

Leap Year. It's one of those oddities of life that's hard to understand, much less to explain.

OK, flashback time. It's February 29th, 1996, and I'm attempting to explain to my 2nd grade class why all of a sudden we have an extra day this month. It's not easy.

"First of all, I need someone to be the sun." I choose Brianna, hand her a big yellow beach ball, and have her stand in the middle of the room. "Now I need someone to be the Earth." I scan the room. Caleb is on the edge of his seat, his hand waving wildly in the air. He leaps up when I nod.

"Now, Caleb, you're going to revolve around the sun. Off you go!" He starts to run in circles around Brianna. "Stop!" I say. I turn to the class. "Does the Earth just move along, or does it spin while it moves?" I ask. "It spins!", they all yell. Teddy falls out of his seat with excitement, or just to liven things up.

"So, Caleb, you'll need to rotate as you revolve around the sun. Can you do that?" I circle my finger around, and he grins and nods. He starts running again, turning in circles as he goes. We all start chanting, "Day! Night! Day! Night!" Whoops - Caleb has careened off course and is almost in the hall.

Time to stop. I motion Brianna and Caleb to sit down again.

"Now, boys and girls, Caleb's gone one whole circle around the sun. How much time has gone by?" "A year!" They shout.

"And how long is a year? They've got this one: "365 days!" Teddy falls out of his seat again.

"No!" They stare at me, stunned. "Not exactly. For the earth to travel all the way around the sun, it actually takes - " I turn to the chalkboard, and say it as I write: "365 days, 5 hours, 48 minutes and 45 seconds."

"Guys, that's how long it really takes for us to go around the sun. The year we use is a little shorter than that. That means every year our calendar gets a little more wrong. After four years we're almost a whole day off."

Twenty-seven foreheads crease in puzzlement. I sigh. Most of us adults can't wrap our minds around this idea, so why do I think these children can get it? Still, I persevere.

"See, if we don't fix our calendar, every year we're going to get ahead of the sun. So every four years we fix this by adding an extra day to our calendar to match up with the sun again."

A long silence. Then Teddy raises his hand. "Can I go to the bathroom?"

Well, it's time for recess, so that's where I end the lesson. I can only imagine how they'll explain this to their parents: "Mom, guess what! Caleb was the Earth and he revolved, I mean rotated, almost into the hall, and Mrs. Jerrie says our calendar's wrong, and can I have a snack?"

Leap Year has such a wonderfully quirky history. The Egyptians figured out a basic system first, and Julius Caesar picked it up from them. But it wasn't quite enough - even with the extra day, after 1,300 years, Europe was ten whole days off from the lunar calendar.

Enter Pope Gregory XIII; he fixed the problem in 1582 by dropping October 5th through the 14th that year. So everyone went to bed on October 4th and got up on the 15th, which got some people pretty upset, because they thought the Pope had made them eleven days older. And if that's not confusing enough for you, get this: some countries refused to change to the new calendar for years, so that if you were sending a letter to, say, Russia, you'd have to write two different dates ten days apart at the top.

And, of course, it's messier yet, since you may have noticed that the 5 hours, 48 minutes and 45 seconds times four doesn't add up to a full day. So once in a while we DON'T have a leap year, to deal with that oddity.

But if we didn't put up with these little adjustments every once in a while, eventually our holidays would wander further and further into the wrong season, and we'd be buying our Christmas presents in July.

Mind you, that's just one calendar, the Gregorian calendar, named after good old Pope Gregory of the lost ten days. Different religions and countries figured out their own ways to handle the problem. Some are based on the moon, or the solar equinoxes, and add or take days away, or even add a month every few years.

So what's my point? Well, here we are, living in a universe that follows its own cosmic rules, and we're stubbornly trying to convince ourselves that we've got it all figured out. But we don't, of course - we just think we do. We see upside down, and our minds turn the images right side up. We pretend we belong on the earth, but only gravity keeps us from floating away. And our invented ways of marking time only loosely grasp even just the simple, stately dance of our home planet around the sun. We just try to keep up as best we can.

Still, the Earth keeps moving around our sun, oblivious to our counting games, and it seems to know what it's doing. So I guess an extra day or two here or there doesn't matter too much.

Happy Leap Year, everyone. Class dismissed!