Different Calendars

Directions: Read about the four most widely used types of calendars to help you answer the questions on your worksheet.

What does it mean if a year is numbered 1300, 1776, or 2000? Who came up with these numbers? Why do some calendars start numbering years backwards? Over the centuries, different cultures and civilizations have measured and tracked the passing of years in different ways. There are four types of calendars used over the course of human history: regnal, continuous, lunisolar, and the Gregorian.

Some civilizations, such as the ancient Egyptians and Chinese, used regnal calendars. The word “regnal” refers to the reigning monarch, which could be a king, queen, or emperor. Regnal calendars counted years based on how long a monarch ruled a country for. For example, if a king ruled for ten years, the first year of his rule would be "year 1," but after he died the numbering would restart for the next king. Scribes and priests kept records of how long monarchs ruled and which order they ruled in.

The Hebrew calendar is an example of a continuous calendar, one that begins and never restarts. It begins on the date that followers of the Jewish faith believe God created the universe and does not restart. Each year simply adds to the last and keeps going. It is a little more than the year 5,770 in the Hebrew calendar.

The Hebrew calendar is also an example of a lunisolar calendar, one where the length of months is based on the orbit of the moon around the earth. This means that some months can change how many days they have. For example, the Jewish holidays such as Rosh Hashanah do not happen on the same date each year. Lunisolar calendars were also the most common in the ancient world and used by the Babylonians, Chinese, Koreans, Hindus, Buddhists, and Greeks.

The last type of calendar is known as the Gregorian (or Western) calendar. It was created 500 years ago in Europe by Catholic monks trying to fix the Roman Empire’s calendar. The name “Gregorian” comes from Pope Gregory XIII, leader of Catholic Church at that time. In this calendar, time begins with the birth of Jesus Christ and is labelled A.D. 1, which is the abbreviation for Anno Domini 1, or “in the year of our Lord, one.” Events that happen before this date are given the title B.C., meaning “before Christ.” This is similar to a regnal calendar but the Gregorian is different because it begins counting backwards from A.D. 1 rather than simply restarting. Each year that is labelled B.C. happened that many years “before Christ” and you have to add that number to today’s year to find out how many years ago an ancient event happened.

The Gregorian calendar has become the most used calendar today because formerly Catholic countries such as Britain, France, Spain, and Portugal conquered or exploited most of the planet starting 600 years ago and forced their ways on other cultures. As a result, the Gregorian calendar remains the official calendar of international trade around the world, even amongst non-European countries. Recently there is a movement to change its abbreviations to BCE and CE, which stand for “before common era” and “common era,” to recognize its use by non-Christians.