Math professor divulges truth about upcoming ‘millennium’

The most common question I get these days is “When does the new millennium begin?” January 1, 2000? or January 1, 2001? The choice embodies the eternal battle of logic and emotion.

Someone (OK, it was me) was quoted by the AP last week as follows:

“The inexorable mathematical logic which cannot be refuted is that the year 2000 is the last year of this millennium and 2001 is the first of the next millennium.”

Well, that was a small part of the whole story I told them, but it does capture the basic truth about the official calendar millennium. I put it this way in the Congressional Quarterly (October 15, 1999):

Imagine a vast army of soldiers, with 1000 in each row. In the first row are soldiers 1-1000, in the second, 1001-2000, and in the third, 2001-3000. The third row starts with soldier 2001.

Or, suppose you work 1000 hours a year. The first year you work hours 1-1000, the second year hours 1001-2000, and the third year begins with your 2001st hour of work.

So we should definitely celebrate the official calendar millennium on January 1, 2001.

(You have to give Congress examples like that, one involving the military and the other involving labor.) But of course there is another side to the story, as I went on to explain:

But there is another millennium to celebrate: the millennium of the 2000s, the years that begin with a 2. This change will affect every check we write, every letter we date. It is exciting to see all the digits roll over for the first time since the year advanced from 999 to 1000 when Ethelred the Second was King of England; as exciting as seeing the odometer in my Ferrari roll over from 99,999 to 100,000 or seeing the whole Senate roll over to 100 new Senators (which probably never will happen, but then again, I don’t really have a Ferrari either). Of course this change in date is what causes the Y2K problems with computers, which will interpret ’00 as 1900 instead of 2000. So maybe it’s safer to wait until the official 2001 to celebrate.

So that’s the battle of logic and emotion that I described to the AP reporter. And that’s half my answer to that most common question. The second half of my answer is to ask my own favorite question:

Question: Where on Earth should the celebration begin?

You may have seen on TV on New Year’s Eve the earlier celebration of the new year in other time zones. The most common answer is Greenwich, England, on the prime meridian, starting place of all time zones. Indeed, a plaque on the Greenwich Old Royal Observatory announces, “The Millennium starts here.” But that is not the final word.

The year 2001, heralding the third millennium, will arrive earlier in England than in America, but it will arrive still earlier farther east in Moscow, still earlier in Japan (that is why it is called the “Land of the Rising Sun”), and so on until you hit the International Date Line and drop back to the previous day. Figure 1 shows a map from The Christian Science Monitor labeled “Fiji First,” showing Fiji right up against the 180-degree meridian of longitude. But that is not the final word either.

The dateline has long had an eastward bulge beyond the 180-degree line, including the South Pacific island of Tonga, situated in a later time zone. But that is not the final word either!

Kiribati, a widespread island nation split by the date line, with a different date in each half, has announced a spectacular relocation of the date line eastward around their boundary, as shown in Figure 2. Now, Kiribati’s Christmas Island will see the new millennium an hour before Tonga.

That’s how my Congressional Quarterly story ended. Now I hear that Tonga is using daylight savings time to recover the lead.

Personally, I hope to go to bed early and find a new millennium waiting for me when I awake.

This article is adapted from Morgan’s upcoming Math Chat Book (Math. Assn. of America, 1999, copyright Frank Morgan), in turn based on Professor Morgan’s Math Chat TV show and column, both available at the MAA web site at The live call-in Math Chat TV show, replete with questions, answers and prizes, will be reprised in Williamstown on Cable TV Channel 17 Wednesday, January 12, 19 and 26, 2000, 7-7:30 pm.