Wednesday, December 02, 2009

Re: Decades

I've noticed several best-of-decade lists, awards, and retrospectives in recent weeks. December 31 will see the end of the aughts, the ten-year block that Time called the "decade from hell." But does the current decade really end in just over four weeks, or does it end in just over 56?

The Gregorian Calendar, the consensus civil calendar throughout the world, includes no year O. This is one of the great embarrassments of western civilization, and it makes arithmetic involving modern dates and ancient dates awkward, but it is a fact and something that we have to deal with. Thus the first century began with year 1 (which is kind of like beginning a day at 1:00 or timing a race with one minute already on the clock when the runners come out of the starting blocks, but that's the way it is) and ended on December 31, 100. The second century began on January 1, 101 and continued through the end of year 200. And so on. (The current century, and millennium, began on January 1, 2001.)

In theory, decades work the same way. The first decade included years 1–10; the second years 11–20; and the one hundred ninety-ninth years 1981–1990. So one could argue convincingly that the current decade will continue until December 31, 2010. But I would like to suggest a less technical approach:

We name centuries with ordinal numbers beginning with the first century (second century, twenty-first century, and so forth). Since our method of naming centuries takes us all the way back to the beginning of our calendar, we must respect that Pope Gregory VIII's calendar starts with year 1 when we determine a century's start and end dates. But we have different naming conventions when it comes to decades. Rather than using ordinal numbers, we use the digit in the tens' place (e.g. twenties, sixties, nineties, aughts, etc.). If you were to mention the "one hundred forty-third decade," few if any people would immediately recognize that you were talking about 1421–1430; but if you were to mention the "fourteen twenties," most everyone would know that you were talking about 1420–1429. As long as we define decades using the years' penultimate digit, 1970 will be part of the seventies decade, even though (unlike years 1971–1979) it is not part of the one hundred ninety-eighth decade.

Now that that's established, I'll get to work on my end-of-decade lists.


Post a Comment

<< Home