Leapin' lizards, Sandy!

M says we have to do a post today because it's February 29th, which we only have one of every four years (with some rare exceptions that he tried to explain but I didn't quite get because I'm--you know--a dog).

Long story short: February has an extra day this year because 2012 is evenly divisible by 4. Short story a bit longer: February, with 28 or 29 days, is shorter than all the other months, which have either 30 or 31 days due to a calendar that is cleverly designed to confuse people.

When M was a little jug-eared kid, he learned a poem about the lengths of the months that went:

Thirty days hath September,
April, June, and November;
All the rest have thirty-one,
Except February, which hath but twenty-eight in fine,
Until leap year gives it twenty-nine.

M says he'll bet a dollar to a doughnut that you learned a version of this, too, and that you probably also made up silly alternatives like this one:

Thirty days hath September,
April, June, and no wonder;
All the rest eat peanut butter,
Except for Grandma--
She drives a Cadillac!

But we digress.

"So the next leap year will be 2016?" I asked M.

"That's a fact," he replied.

"And the most recent one before now was--uh--2008?"

"Yep. And 2004 and 2000 before that."

"Will 2100 be a leap year?" I probed.

"Actually, no," he said. "Most people probably believe it will. I thought so, myself, for most of my life. But then I learned another rule that says: Years that are evenly divisible by 4 and also 100 are not leap years unless they're evenly divisible by 400 as well."

"That's not in the poem," I said.

"Yeah. Sorry to muddy the water."

We found an article on Wikipedia that's all about leap years and leap days and how and why different calendars adjust for them. For more about these topics than you can throw a stick at, go here. But to the masses of you who think there's such a thing as knowing too much, let me just say . . . you might be right. Go walk your dog.