An Extra Day and a Hot Mess

Sometime around the year 1235, Johannes de Sacrobosco, a monk and astronomer teaching at the University of Paris, published his Du Computo Ecclesiastico, an in-depth study of the hot mess that is the history of the calendar in all its various imaginings and recalculations through the years.

Though I haven’t read it, the history rumor mill suggests the book is pretty scholarly. Sacrobosco definitely had a lot of things to say about the way the passage of time should be measured, including a few suggestions for reckoning the Julian calendar to solar and lunar observations and calculations. By his day, the equinoxes and solstices had already experienced a pretty significant backwards slippage in time.

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Julius Caesar wishing February had been a little bit longer, because March wasn’t looking so good for him. Vincenzo Camuccini / Public domain

The book also includes a story about how the calendar ended up in such a terrible fix in the first place, like that time the month of February became comically short because Augustus Caesar decided to borrow a day for his own namesake month of August so that it would be every bit as long as the previous month named for his dad.

February is comically short, not only because it usually has twenty-eight days instead of the more traditional thirty or thirty-one, but because it follows January, which at least in my corner of the world is the longest darn month of the year. It’s bleak and cold and filled with the junk you put off during the holidays. Oh, and it follows the holiday season, which is as fun as January isn’t.

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Any month that starts off with a groundhog is pretty okay in my book. Picture by hatlerbratton, via Pixabay

Like it has most years I can remember, February has kind of flown by comparison. This shortest month comes with a furry mascot, a celebration of love, Girl Scout cookies, the start of baseball spring training, and slightly brighter days. Mine probably went especially fast, too, because it included a book launch and the corresponding flurry of activity. My calendar has actually been kind of a hot mess.

But as “not as awful as January” as February is, it does kind of get the shaft, even in leap years like this one. Had I been in Sacrobosco’s place writing a treatise on the convoluted history and problem of calendars (which I assure you no one would call a pretty scholarly work), I also would have included that story about Augustus Caesar lopping off February’s end, because it’s a pretty great one. Of course, it wouldn’t have been true if I’d written it, either.

It turns out there’s plenty of evidence that the calendar’s multitude of problematic and somewhat sporadically assigned month lengths predated both Augustus and Julius. The latter did do his level best to fix it, consulting with the astronomer Sosigenes from Egypt to come up with a 365-day year that corrected with a leap day every fourth year.

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Pope Gregory XII, a man whose calendar was not a hot mess. Justus van Gent / Public domain

Not bad. But it didn’t fix the problem indefinitely and it wasn’t until three hundred fifty years after Sacrobosco’s book that Pope Gregory XII made a really good change to the plan. That’s when it was decided that the calendar everyone would use (except for those who didn’t feel like it) would include 365 days, with a leap year every fourth year, except for a century year, unless it could be evenly divided by four hundred.

Simple, no?

But it has more or less worked since then with a large chunk of the world buying in to its use, or at least more or less understanding it so that business can be conducted with relative ease all 365 days, 5 hours, 48 minutes, and 46 seconds of the year.

It’s still not perfect and will need more corrective action over the course of millennia. Evidently the rotation of the earth isn’t even entirely consistent, making our measurement of time a little less precise than we’d probably like to think. But there are astronomers who regularly work on that problem and keep us all on track by occasionally adding an extra one-Mississippi to the clock. I imagine most of us aren’t much bothered.

In fact, other than the approximately 4.2 million “leaplings” world wide who will be celebrating their birthday this Saturday or the hopelessly romantic ladies who will be exploiting a silly tradition and proposing to their fellas, a lot of us probably barely even notice February 29th when it rolls around.

Unless you’re like me and your calendar is a little bit of a hot mess. Personally, I plan to make good use of this February’s extra day.