A Brief History of the Calendar

by David Harper, PhD, FRAS


It's the year 2000. We stand at the dawn of a new century, a new millennium. We can't even begin to imagine what the next thousand years will bring, but if the last thousand years are any guide, the third millennium will hold wonders.

But wait a moment, and ask yourself: why 2000? Why is this year so special? And why are we celebrating its birth on January 1st?

Our lives are bound up with the calendar. We use it to plan our future: the annual round of work, meetings, appointments, holidays, birthdays and all of the other events in life. We write them in our diaries so that we won't forget.

Our diaries also tell us of the other events of the coming year: public holidays, religious festivals, weekends, the waxing and waning of the Moon.

The calendar helps us to look back, too. The date of our birth is our personal milestone in the calendar. The historian looks further - to 1945 or 1812 or 1066. They seem to be just numbers, but we know instinctively that they are more than that. Each event, public or personal, great or small, has a day and a month and a year which fixes its place in time.

We take the calendar for granted because it's always been there, day following day, month following month, year following year. We know that it has rules - every fourth year is a leap-year and so we add an extra day to February. But the lengths of the months are irregular, some 31 days, other 30 and poor February only 28 days in three years out of four. Easter seems to move at random. The days of the week provide some kind of regularity, but why do we have seven, and why are they named after a mixture of planets and Norse gods? And why do the British pay their taxes on April 5th?

Our calendar can trace its roots back over 6000 years to ancient Egypt. Its story features Julius Caesar, the Council of Nicaea (which gave us the Nicene Creed), a small Russian monk called Denis, the Venerable Bede and Pope Gregory XIII.