How We Get Our Calendar?


In this post, I am going to tell you how we get our modern day calendar and what is BC, BCE, AD, CE.


Who created the first calendar?

The first calendar was created by Sumerians, the earliest civilization,  in Mesopotamia. The Sumerians used the sighting of the first full moon to mark a new month. There are 12 months in a year. Each month has 29 to 30 days. One year had 360 days and an extra month is added every four years.  Since this calendar is based on the position of the moon, it is called classified as a lunar calendar.

Ancient Egyptian later observed the position of the sun as Earth turned around it  and noticed that the year was longer than the moon cycle. The Egyptians then switched to a solar calendar with 365 days in a year. A solar calendar is based on the revolution of the earth around the sun.

The Julian Calendar

Since then, there were other various calendars created by the Babylonians, the Greek, the Chinese, the Hebrews and the Romans.

The Roman general Julius Caesar advised by the Alexandrian astronomer Sosigenes, adopted the Egyptian solar calendar, taking the length of the solar year as 365 1/4 days. This calendar called the Julian calendar was adopted in 46 BC. 

To be precise, the solar year is actually 365 days, 5 hours, 48 minutes, 45.25 secods). Hence, with the Julian calendar, it will cause the calendar dates of the seasons to be short of one day per century.


The Gregorian Calendar

In 1582, a conference held by Pope Gregory XIII made refinements stating that no century year is a leap year unless it is exactly divisible by 400 (e.g., 1600 and 2000). This keep the Gregorian calendar accurate to within one day in 20,000 years.


Our Modern Day Calendar

Our modern day calendar is the Gregorian Calendar which has since been adopted by countries all over the world. It is named after Pope Gregory XIII. It is based on the revolution of the earth around the sun.


What is BC and AD?

We read earlier that the Julian Calendar was adopted in 46 BC. What does BC stands for? BC stands for “before Christ”AD stands for Anno Domini, Latin for “in the year of the Lord”, while BC stands for “before Christ”. This means that the years on the Gregorian calendar are calculated in relation to the birth of Jesus. 

The idea to count years from the time of Jesus Christ was first proposed in the year 525 AD by Dionysius Exiguus, a Christian monk. Standardized under the Julian and Gregorian calendars, the system spread throughout Europe and the Christian world during the centuries that followed.

Note that the exact year of Jesus’ birth is a topic of debate among scholars, but most believe that he was likely born between 6 and 4 BCE. There is no dispute over the fact that the birth of Jesus is used as the starting point of the present day calendar. However, there are debates over when was the actual year of Jesus’ birth and whether the present day calendar has accurately reflected the year of the Lord.

What is BCE and BC?

In some documents and websites, you may see years abbreviated with “CE” or “BCE” instead.  CE stands for “common (or current) era” and BCE stands for “before the common (or current) era”.

These abbreviations has a religion neutrality but has a shorter history. It started around 1700. The movement towards BCE/CE has not been universally accepted, and BC/AD is still more widely used, even though BCE/CE has been in the mainstream since the 1980s.

Think About It

Whether it is BC and AD or BCE and CE, the fact is, the calendar years have been marked to have a section before the birth of Christ and a section after the death of Christ.

Give it a thought. Throughout history, there were many kings who conquered and established great empires. Many built statues to have their people worshipping them as gods. Yet, all these great kings are dead and none has an impact on mankind timeline, not even Noah from whom the whole world originate from.

Yet, our calendar is referenced to the birth and death of Jesus. Such impact can only be the approval and fingerprint of the highest supreme power, Creator of this universe –God. This in itself, is a clear evidence that Jesus is the Son of God, Jesus is God.