Thirty days hath September,
April, June and November,
save February -
That's the real odd one
By MICHAEL JAMISON of the Missoulian
KALISPELL - Today is an extra, a bonus, a freebie, like the $5 bill you found in the pocket of that spring coat you hadn't worn for a year.
Spend it well. Because you won't get another for four more years.
This year, 2008, is a leap year, which means February comes with a whole extra day - and a Friday at that.
The calendrical convolution that is this last day of the second month of the fourth year is actually the cultural wreckage left behind from a collision between physics and metaphysics.
Scientist Stephen Jay Gould unraveled the arcane mathematics of it all in his slim but elegant volume, “Questioning the Millennium: A Rationalist's Guide to a Precisely Arbitrary Countdown.”
The story begins in the days of Julius Caesar, with the first chapters written in the stars - the concepts of days (Earth's rotation), months (moon's revolution) and years (Earth's revolution.)
Trouble is, none is an easy multiple of the others, a fact that has plagued calendar makers from the beginning.
A year is not, as we conveniently assume, a simple cycle of 365 days. Rather, it's a cycle of 365 days, five hours, 48 minutes and 45.96768 seconds. In other words, a year is about a quarter of a day too long, and those extra bits tend to pile up after a while.
Back in 45 B.C., Julius Caesar absorbed those bits in his Julian calendar by adding a leap year every fourth year - an extra day, Feb. 29.
His was a closer approximation of celestial reality, but still not quite on the mark. A year was not, unfortunately, exactly 365.25 days long. It was 365.2422 days long.
The difference, so seemingly slight, tallies up to about 11 minutes and 14 seconds each year. Caesar, it seems, had overreached.
The extra continued to pile up, at the rate of about seven days every 1,000 years.
Who cares? Well, pretty much everyone in the Middle Ages. Farmers and astronomers cared, because the additional days meant “fixed” dates - such as the spring equinox or the winter solstice - kept sliding around the calendar.
Priests cared, too, because celebrations such as Easter also meandered through the calendar.
By the 16th century, Pope Gregory XIII had had enough. A full 10 days had stacked up, and he decided to put a stop to the problem once and for all.
He called on his mathematical adviser, Christopher Clavius, who in 1582 unveiled the Gregorian calendar, which we still use today.
Clavius' first order of business was to clear out those extra days. The pope handled that from the top down: he simply declared that, in 1582, Oct. 5 through 14 never happened. That year, the day after Oct. 4 was Oct. 15, and too bad for you if your birthday fell in between.
(England didn't follow suit until 1752, and by then had to drop 11 days, Sept. 3-13; and Russia didn't lose the extra days until 1918, which is why the “October Revolution” is celebrated in November.)
Clavius' second charge - to stop the continued accumulation of days - was trickier. He pulled it off by keeping Caesar's leap years, but tempering them by dropping the extra day at each century marker. Every 100 years, when the century rolled over, the leap year was skipped - no Feb. 29.
But as with Caesar's attempt, Clavius' manipulations overcorrected the problem. And so he added yet one more layer - he restored the missing leap years at every fourth century boundary.
That's why there was a Feb. 29, 2000, but will be no Feb. 29, 2100.
You might call those every-fourth-century days double-extra-bonus days, and you would be very wise to spend them well, as they come only once every 400 years.
The calendar - and the whole hind end of February, really - was, and remains, a complicated mess, but it's the only mess we have: Add a day by leap year every four years, remove leap years from century boundaries, and put the leap year back in at centuries divisible by four.
Of course, even then we're still off by 25.96 seconds every year, which means we'll have to find a way to pick up one extra day every 2,800 years or so.
Noodling out how to do just that, in fact, might be a very productive way to spend your extra Friday.
Who knows, craft a stylish solution and you, like Caesar, just might get a calendar named after you.
Reporter Michael Jamison can be reached at 1-800-366-7186 or at mjamison@missoulian.com
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