Have you heard all the talk about the new Millennium? Do you know what a millennium is? It's more than just a big New Year's Eve party. A millennium is a period of 1,000 years - just like a decade is 10 years and a century is 100 years.

Traditionally, time has been measured in terms of the number of years from the beginning of a some major event, such as a ruler's reign. For instance, if we did this today, Americans might say that this year is Clinton 7 - the seventh year of Bill Clinton's presidency. Or maybe we would call our year Moon 30 - because it has been 30 years since man first landed on the moon. That's why we call our current year "1999" because we believe it's been 1,999 years since Christ's birth. But that isn't necessarily accurate...

Expert Fact Did you know that January 1, 2000 isn't really the beginning of the new millennium? The new millennium really starts on January 1, 2001. Provided by: Richard Curtis, Executive Editor, Washington Report on Mid East Affairs

For one thing, our modern calendar/counting system starts with year 1 instead of year 0. That is, we go straight from 1BC to 1AD, or 1BCE to 1CE. So, if Jesus was born in Year 1, then he was one year old in Year 2, and he was 9 years old in Year 10. Year 100 marked 99 years since his birth, and year 101 marked the 100th anniversary of his birth. So with the same logic, we can see that Year 2000 is only 1999 years since he was born, and we'll have to wait until the year 2001 for Christ's 2,000 year birthday!

And now here's another confusing twist! The man who created the calendar we use today, Denis the Little, called the year of Jesus' birth 1AD. But, more recent research has determined that Jesus was actually born a few years earlier than Dennis thought - that is, somewhere between 6 BC and 4 BC. Yes, Christ was born "before Christ"! That means that if you are interested in celebrating 2000 years since Jesus's birth you missed the party - it happened somewhere between 1995 and 1997!

Do you know what CE and BCE stand for? CE stands for Common Era, and BCE stands for Before Common Era. We used to say BC for "Before Christ" and AD for anno Domini, which is Latin for "in the year of our Lord." In recognition of the fact that both Christians and non-Christians use this dating system, historians have now switched to the more secular "common era."

In 1582 Pope Gregory XIII adopted some small changes to Dennis' original calendar system. These changes more accurately reflected the astronomical year. Today, we call our calendar system the Gregorian calendar. Our years are based on the earth's circuit around the sun.

There are lots of other calendar systems in the world. According to one source we read, more than half the people in the world use a different calendar than we do. Further, many don't even use the same months as we do.

In the Muslim world we are in the year 1420 AH (Anno Hegirae). It has been 1,420 years since the Prophet Mohammed moved from Mecca to Medina, where the Muslim religion he preached began to take hold. Today in Muslim countries many people use the Islamic dating system in private life, but use the Gregorian (western) calendar for civic and business affairs. In the Muslim tradition, months are lunar - that is, they are tied to cycles of the moon. Lunar months do not correspond to the sun-based year. For example, the Muslim lunar month of Ramadan is in December this year, but by 2002 CE it will be in November, and by 2010 it will be in August.

secular - non-religious calibrate - to divide or mark in sections

Jewish people use yet a different year - we are now in 5760 according to the Jewish measurement of time. This is the number of years that Jews believe it has been since God created the earth. In Israel, newspapers print both the Gregorian year 1999 and the Jewish year 5760. After January 1 the year will still be 5760. The Jewish New Year, called Rosh Hashanah, falls in September or early October. Months in the Jewish calendar are lunar, but they do not rotate around the year like the Muslim months do. Instead, every 2-3 years a 13th month is added. The next 13-month year in the Jewish calendar will be in 2000 CE.

Hinduism, Buddhism, and other religions also have their own dating systems. For instance, the Buddhist Era (B.E.) measures years since Buddha's death in 543 BCE. 1999 CE is 2542 B.E. Buddhist months are lunar, with a leap month similar to the Jewish calendar.

With so many calendars in the world, why is there so much hype about 2000? Over the past few centuries, for better or for worse, Christians have had tremendous influence on the Western World. Christians and non-Christians alike have adopted the Gregorian calendar. It is easier to communicate and do business if everyone uses the same year. Perhaps as a result, our calendar seems to have become detached from its association with religion.

So, with religion out of the picture, perhaps we can better understand the interest in 2000 rather than 2001 as the mark of the "millennium." In our culture people are attracted to numbers like 10, 25, 50, 100, and 1000. We like to mark our time in these numbers, and we like to look back and reflect on where we have been in the past 10, 100 or 1000 years.

Related Links: More details about the millennium, the Gregorian calendar, and Denis the Little. More details about the history of the Gregorian calendar Has a program that converts dates between Gregorian, Julian, Islamic, and Jewish calendars. Slow to download, but fun to play with. This site also has more information on the Gregorian calendar and its precursor, the Julian calendar. Describes many different calendar systems in use today. Detailed history and explanation of the Jewish calendar

Yet does time really require a calendar? Time measurement is a human convenience. It is influenced by cycles of the sun, moon, and earth, but calibrated in methods of our choosing. Before clocks chimed in towers above towns and cities, did time exist? Before it became confined to mechanic dials strapped to wrists and perched on mantels, did time, like clouds, roam free? Light and dark, sun and moon, tide in and tide out… the earth has a rhythm like the tick-tock of a clock. The only question is how we choose to measure it.