January 3, 2000

Is It Really the New Millennium?

Did you celebrate the millennium on Friday night? Some people didn't, because they believe that the new millennium hasn't started yet. Still others believe that it should have started a few years ago. 

Consider this fact: The Gregorian calendar, which is used widely throughout the world, does not include a year 0. Chronologically, the year 1 B.C. is followed by the year 1 A.D. Taking this into account, on what date will we have completed 2000 years of the A.D. era?

If you start counting from the year 1, then two thousand years have elapsed on January 1, 2001. But perhaps you should have celebrated the new millennium several years ago.

The Gregorian calendar, developed by a sixth-century monk named Dionysius Exiguus, is based on the birth of Jesus as the "starting point" for year 1 of the A.D. era, but scholars think that he was actually born a few years earlier, anywhere between 7 and 3 B.C.

If Jesus was born in 3 B.C. and there is no year 0, can you figure out when you should have celebrated the millennium, i.e., when two thousand years have passed since Jesus' birth?

If Jesus was born in 3 B.C., he would celebrate his 2000 birthday in 1998 A.D. To make the calculation, you add the absolute values of the years in the B.C. era and in the A.D. era, and subtract 1 to compensate for that missing 0: 3 + 1998 - 1 = 2000.

Let's take a closer look at the calculations. When a baby is born, we give her age in days, weeks, and months until her first birthday. She is "one" not on the day she was born, but after one complete year has gone by. Similarly, when the world turns 2000, it has lived for two thousand years, which means that two complete millennium have been completed.

Let's continue this line of reasoning, while remembering that the common Gregorian calendar doesn't have a year zero. A baby born on the first day of the original millennium, January 1, 0001, would only celebrate his first birthday on January 1, 0002. His 100th birthday would be on January 1, 0101; his 1000th birthday would be on January 1, 1001. See the pattern? The new millennium should be begin on January 1, 2001.

The concept of zero is integral to our understanding of mathematics today. It is the base from which we define both whole numbers and integers; it is the organizing point for a number line. Yet the number zero was only "discovered" in India and almost simultaneously by the Mayans in the early centuries of the first millennium. The Europeans didn't adopt zero for about another thousand years. For learning more about the role of zero, see the Destination Math session, Exploring the Number Line and Absolute Value.

So, is it the new millennium? Maybe the scientific community is right and we really have another year to wait. Or maybe we should follow our gut feelings and compensate for the Gregorian calendar's lack of 0, because after all, 2000 looks like the new millennium. It's all "zeroed out" for a new beginning.

For an in-depth, entertaining article on the question of the beginning of the millennium, the importance of zero, and calendars in general, see Zero, by Dick Teresi, first published in the Atlantic Monthly in July, 1997.