AD and BC: Understanding the Dates

BC/BCE and AD/CE timelines explained. Understand how the various conventions are used to denote time in history.

In academic work, most of the time you will come across dates (years) that will be written as 2000 AD, 500 BC, and so on. So what is the AD and BC when it comes to years? Let’s understand how time works and learn more about the various labels that are used with calendars.

Highlights:

• A.D. is the period AFTER Jesus was born (A.D. stands for anno domini, or “in the year of our lord”)
• B.C. is the period BEFORE Jesus was born (B.C. stands for before Christ)
• There is no concept of “zero” year in the modern calendar. So, in this system, the year Christ was born is designated as 1 A.D., and the year preceding it is 1 B.C.

Here are some Examples.

• 450 BC means 450 years before Jesus Christ was born
• 2 AD is actually 1 Year after Jesus was born (remember, Christ was born on 1 A.D.)
• 2000 AD means 1999 Years after Jesus was born (but you can say almost 2000 years).

What is CE and BCE?

In recent years, the labels CE and BCE have started becoming popular.

• CE means “Common Era” and is the same as AD
• BCE means “Before Common Era” and is the same as BC

An important reason why many academicians are adopting BCE/CE is because of its religious neutrality. It does not sound ‘Christian’.

Examples

• 2020 CE is same as 2020 AD
• 550 BCE is same as 550 BC

Where to place the labels?

• BC should appear after the numerical year, while AD should appear before it (1500 BC, AD 1200)
• BCE and CE should both appear after the numerical year (1050 BCE, 1266 CE)
• Periods may be used after each letter (500 B.C., A.D. 1166, 1200 B.C.E., 550 C.E.)

Note: Of late, it has been observed that many academicians are now using “AD” after the year.