Oysters vs. Porcupines Unearthing the Roots of the Century Dispute by Laurence McGilvery copyright 2000 Laurence McGilvery. Midnight, 31 December 1999 If this longawaited moment were a bell ringing the highest note on the scale, it would be flat. If it were your last gasp attempting to break the mile, you'd be one step short of the finish line. If it were the final page in a lurid murder mystery, you'd never find out whodunit. Do centuries and millennia close with years ending in 99 or 00? That question, what Ruth S. Freitag of the Library of Congress calls the "minor imbecility" of the Century Dispute, has diverted some of our most inventive thinkers for at least three hundred years. For example:
THE PORCUPINE, Philadelphia, 1799 In response, the thunderous voice of logic made short work of knownothings:

Tortured Sophistry Porcupines 1, Oysters 0 The nearly universal cliché of the calendar as an odometer is exactly wrong. When the zeroes roll over on your nearly new car, they mark the end of its 2000th mile. When the clock hands point straight up at midnight on New Year's Eve, the 2000th year is only beginning. The first is a measurement, the second, a date. Confusing the two produces the grief and folly of the Century Dispute. Income Tax Day can be written 4/15, butquickly!how many months is that? Not 41/2, but 31/2. The calendar always reads one unit higher than its equivalent quantity or measurement. Invisible But Essential  What Zero Year? Of all the confusions produced by the Century Dispute, the socalled zero year is the most irritating. Briefly, it inserts a year named zero between B.C. and A.D. to make centuries and years come out even. The first decade would end on New Year's Eve of the year 9, and the second millennium would end in 1999. The U. S. Naval Observatory blithely states on its website, "Today it is obvious that a year designated 1 would be preceded by year 0, which would be preceded by year 1, etc." Well, not quite. The calendar already has a perfectly good zero, the dimensionless moment that separated B.C. and A.D. In "The Nothing That Time Forgot" (New York Times, November 13, 1999), Robert Kaplan and Dick Teresi asserted that leaving out the zero year "is like counting backward from 2001 directly to 1999, skipping 2000." Here we see with awful clarity the flaw in this idea. The writers have confused two of the three common roles of zero. First, its sloping shoulders and empty belly signify nada, nil, nix, the pocket empty or, better, the balance on a fully paid bill. Second, it stands for ten in our decimal system, giving birth to the glorious powers of ten which every citizen should understand (see the wonderful book Powers of Ten). Third, it is a dimensionless division, not a quantity or a duration. Any scale that measures continuously between plus and minus values contains this zero mark. Think of the visitor straddling the 0° meridian at Greenwich, England, one foot in the eastern hemisphere and one in the western. The year 2000 is a multiple of ten; the zero point is a multiple of nothing. The other half of the zero year argument states that anniversaries crossing the B.C./A.D. divide occur a year too soon. Here is a simple example: 30 June 5 B.C. to 30 June A.D. 5 is not ten years but nine. The reason is not a missing zero year but the fact that the two outside years, 5 B.C. and A.D. 5, each contain only six months. Together they make one full year. The equivalent span on a thermometer is 4.5 degrees to +4.5 degrees. If this arcane issue caused constant difficulties in our daily lives, it still would not be acceptable to fix it by destroying the symmetry of the calendar. It is, in fact, quite harmless. Let the astronomers and the archaeologists and their kin to whom it does matter remember that they must add one when crossing the B.C./A.D. divide, if they want anniversaries to appear to match. They are all up to that challenge. 
Cardinals and Ordinals What I will call calendar time encompasses days, months, years, centuries, and millennia, as well as seasons, historical eras, and geological periods. Entertainments divide into acts and scenes or movements; sporting events play out in quarters, innings, rounds, matches, and laps. All take time to unfold, and all are named as they begin. Alland this is importantare ordinal numbers, even when they look like cardinals. The new year is not 2000, like a milestone, but the 2000th year. It has a beginning, a middle, and an end. The difference between cardinal numbers and ordinal numbers bears on the Century Dispute without exactly explaining it. Cardinal numbers say how much or how many: 12 eggs, $4.73, 21 years old. Ordinal numbers tell position in a sequence: 2nd base, Fifth Avenue, in her 22nd year. The number of this page is an ordinal. So is a highway mile marker or a street address. 9 East Tenth Street combines two sequences. The names of yearsA.D. 1, 1066, 1455, 2000are ordinal numbers masquerading as cardinals. A date links three together: 1 January of A.D. 1 is the first day of the first month of the first year. Circa A.D. 525, a Scythian monk named Dionysius Exiguus ("Dennis the Humble") invented the Christian Era, though he calculated it four to seven years too late, according to most Biblical scholars. The Venerable Bede, the first great English historian (672/73735), popularized it two hundred years later. Both used ordinal forms to name dates. Bede's Ecclesiastical History of the English People (Book I, chapter ii) contains the first written expression of the era we now call B.C.: "ante uero incarnationis Dominicæ tempus anno sexagesimo" ("in the sixtieth year before the time of the incarnation of the Lord," which is 61 B.C.). Those ancients knew the true names of years. We have forgotten. An Impartial Despot A Moving Finger 
Geniuses So how did they know to count by ordinal numbers? They didn't. A calendar is a map in time, and the "here" of that map is the present. Long before they had numbers, our heroesin many times and placesmust have begun to divide the seamless flow: today, yesterday, tomorrow. They could only note each day as they lived through it, whether they measured its beginning from midnight, dawn, noon, or the appearance of three stars in the twilight sky. You would have done the same. Does It Matter? Does it matter? No, for this 2000year cycle has no relation to nature. Even its reckoning, calculated with the best of intentions, is off by four to seven years. Hillel Schwartz, author of Century's End, delights in pointing out that any moment is a millennium away from something. The turn of this 1999th year is an arbitrary scratch in a continuum which has lasted 4.56 billion years since Earth's formation and 12 to 15 billion years since the Big Bang. The rocks, oceans, and skies are not humming in a terrestrial crescendo as the hour mounts to midnight. The wheeling heavens will not stumble one nanosecond as our puny clocks tick over. Much of humanity already has shrugged its collective shoulders. The rest of the animal kingdom munches on, completely unconcerned.  Counting the Minutes & Seconds "What a funny watch!" Alice remarked. "It tells the day of the month, and doesn't tell what o'clock it is!" "Why should it?" muttered the Hatter. "Does your watch tell you what year it is?" "Of course not," Alice replied very readily: "but that's because it stays the same year for such a long time together." Clock time is embedded within calendar time, yet we usually count it just like measurements. What's going on? With her characteristic common sense, Alice recognized one likely reason. Hours are short; years are long. Still more important, calendar time is ancient, and clock time is recent. The first public mechanical clocks were erected in Italy around 1300. Accurate clocks that could count minutes and seconds were theoretical ideals until the technological revolution of the midseventeenth century. Only in the nineteenth century did the rise of railroads and the need for reliable schedules produce widespread precision in timetelling. Calendar time is 35,000 years old or more, accurate clock time, less than 400 years. No wonder there is a mismatch. Of course those seventeenthcentury rationalists would simplify clock time by adding it up like other measures. Of course they would follow the example of the modern clock face itself, which graphically displays the passage of time as sums of hours, minutes, and seconds. And of course they would leave calendar time alone. What possible benefit could there be in changing it except at century's end. 
Does it matter? Yes, but only because if it does not, if the beautiful rigor of number can be so trivially cast aside, then all clarity inevitably will suffer. 2000 Copyright 2000 Laurence McGilvery 