Whether you’re studying History or Literature, confusing dating notations such as AD 2000 or 300 CE are always going to be there. Perhaps it was easier when only the BC-AD calendar marking system was used. These other acronyms like BCE, CE, BP, etc. started slipping in the books slowly and messed up our year counting system. But, you know, even though the letters are different, the new system is not that difficult to understand.
| Notation | Full-form | Short Description |
|---|---|---|
| BC | Before Christ | before the birth of Jesus Christ |
| AD | Anno Domini | A Latin phrase that means ‘in the year of our lord’ (refers to Jesus Christ – in the year that our Lord Christ was born) |
| BP | Before Present | before the year 1950 |
| BCE | Before Common Era | equivalent to BC |
| CE | Common Era | equivalent to AD |
| ka or kyr or KY | kilo annum | a thousand years |
| c. or ca. | Circa | The Latin word for around or approximately |
| cal | Calibrated |
What we are studying here – Literature, Literary Movements, Philosophy, History, Linguistics – all these subjects use these notations. So, it was best to clear our concepts before moving on to them.
Are you ready? Let’s dig in!
| CONTENTS: What is AD? – Does AD not stand for ‘After Death’? – Who started the system of counting years based on the of birth Jesus Christ? – What is the right way of using AD in calendar notation? What is BC? – What is the right way of using BC in calendar notation? What is CE? – What is the right way of using CE in calendar notation? – Are AD and CE the same? What is BCE? – What is the right way of using BCE in calendar notation? – Are BC and BCE the same? Is there a year Zero? How do they count years? – When was Jesus born – 1 BC or 1 AD? – Is there a year Zero? – How do they count years? What is cal? What are Calibrated Dates? What is BP? – Is BP the same as BC? – How do you convert BP to BC/AD or BCE/CE? – Why use BP and BC together? What is ka? What is circa? (c. or ca.) Frequently Asked Questions about timelines: – Is it okay if we don’t use the notation? – How many BC years were there? What was the last BC year? – What is the right word order & punctuation for the use of Calendar Notations? – In which timeline are we living – AD, BC, BCE, or CE? – What is the point of C.E and B.C.E, since it still determines common eras by the birth of Christ? – Why Have Some People Adopted BCE/CE? – Why do we still have BC-AD despite having BCE-CE? Conclusion |
What is AD?
The acronym ‘AD’ stands for Anno Domini, a Latin phrase for “in the year of our Lord” (the year Jesus Christ was born). So, every year that comes after the birth of Jesus, falls under the “AD” category. That makes the year in which Jesus Christ was (theoretically) born 1 AD – it was his first year.
Does AD not stand for ‘After Death’?
Many people think that ‘AD’ stands for ‘After Death’. It is wrong. Because, if it was true, how would we justify or call the years that Jesus lived?
Who started the system of counting years based on the of birth Jesus Christ?
In 525 AD, Dionysius Exiguus, a Scythian Christian Monk proposed the idea of using Jesus’s birth as the frame of reference for identifying the years. (525 years after the birth of Jesus). Therefore, he is also known as the ‘Inventor of Anno-Domini Dating.’
What is the right way of using AD in calendar notation?
As per the Latin convention, the acronym ‘AD’ usually precedes the year. For example, AD 2021. If we are referring to a century, period, or millennium, the acronym ‘AD’ usually comes after the period. For example, fifth century AD or 3rd millennium AD, etc.
What is BC?
The notation ‘BC’ stands for ‘Before Christ’. So, all the years that happened before Christ’s birth fall into the “BC” category.
What is the right way of using BC in calendar notation?
As per English usage, the acronym “BC” usually follows the year. For example, 2021 BC. If we are referring to a century, period, or millennium, the acronym “BC” usually comes after the period. For example, fifth century BC or 3rd millennium BC, etc.
What is CE?
The acronym ‘CE’ stands for Common Era or Current Era. Although CE doesn’t directly point to Christ’s Birth, it still uses Christ’s birth as the point of reference.
What is the right way of using CE in calendar notation?
As per English usage, the acronym ‘CE’ usually follows the year. For example, 2021 CE. If we are referring to a century, period, or millennium, the acronym ‘CE’ usually comes after the period. For example, fifth century CE or 3rd millennium CE, etc.
Are AD and CE the same?
In the calendar notations, AD and CE point to the same year. AD stands for Anno Domini (The year of our lord) and CE stands for Common Era. Since CE still uses Christ’s birth as a point of reference, without saying it explicitly, AD and CE are the same. Therefore, AD 2021 = 2021 CE.
What is BCE?
The acronym ‘BCE’ stands for ‘Before Common Era’ or less commonly ‘Before Current Era’. Just like ‘CE’, ‘BCE’ is a secular version of ‘BC’. It doesn’t directly use the word ‘Christ’ but uses the words ‘Common Era’. But, 500 BC = 500 BCE.
What is the right way of using BCE in calendar notation?
As per English usage, the acronym ‘BCE’ usually follows the year. For example, 2021 BCE. If we are referring to a century, period, or millennium, the acronym ‘BCE’ usually comes after the period. For example, fifth century BCE or 3rd millennium BCE, etc.
Are BC and BCE the same?
In the calendar notations, BC and BCE point to the same year. BC stands for Before Christ and BCE stands for Before Common Era. Since the birth of Christ & the Common Era is apparently the same, BC is the same as BCE. 300 BC = 300 BCE.
Is there a year Zero? How do they count years?
When was Jesus born – 1 BC or 1 AD?
When Dionysius Exiguus proposed this idea in 525, he assumed that Jesus was born in what we call 1 AD. But, it was later found out that ironically, Jesus Christ was born in c. 4 BC – 7 BC. There is a lot of debate about this. They are multiple arguments. But, it was not 1 AD – this is what they are sure about. Most biblical scholars and historical researchers believe that Jesus was born before 4 BC.
Is there a year Zero?
There is no Year Zero in the AD-BC system of marking years. You celebrate December 31, 0001 CE, at midnight, you enter January 1, 0001 AD!
Now, let’s consider that the “year of our lord” – the AD was actually the year Jesus was born.
That makes it 1 “AD”. (And we assume that the date of his birth was 1st January, 0001 AD.)
This makes the year before that and all the years before that the years “Before Christ”. Because obviously, they have happened before Christ’s birth – 1 year before Christ’s birth, 2 years before Christ’s birth, and so on…
And so, why would we need year zero? When a baby is born, the first year of its life begins and when it completes, we say – the baby has turned 1. So, that whole year is the 1st year, right?
How do they count years?
The number line in Arithmetic uses Zero as the point of reference. Look at the image below:
All numbers on the right side of (or those that come before) “0” are positive and those on the left side of (or those who come after) “0” are marked negative. -200 is greater than -300 whereas 300 is greater than 200.
Similarly, we are using Christ’s birth as the “0” mark on the number line. So, BC 4 happened 2 years earlier than BC 2.
That means we move from
3000 BC to
2000 BC to
1000 BC to
Christ’s birth to
AD 1000 to
AD 2000 to
AD 2021
And, so on.
But the main difference between the number line and the year mapping is:
| Number Line | Year Mapping |
|---|---|
| There is a neutral point “0”. | THERE IS NO YEAR “0”. |
| The specific point is marked as “1” & not the entire space between 0 and 1. | The entire space between 0 (the theoretical birth of Christ) and the next point is marked 1. |
| There are infinite points between 0 and 1 (or any two consecutive integers) | There are exactly 365 (or 366) days between 2 consecutive years. |
| The difference between -2 and +3 is 5. | The difference between 2 BC and 3 AD is 4 years. There are 4 laps as we don’t have a Year Zero. Look at the image below. |
There are exactly 4 years between the date August 15, 03 BC and August 15, 02 AD.
What is cal? What are Calibrated Dates?
After the scientists started using Carbon Dating to find out the dates of an item, they realized that it gave them dates that didn’t match with the calendar years. The method Carbon Dating a.k.a. Radiocarbon Dating a.k.a Carbon-14 Dating helps us find out the age of an object from the radiocarbon content in it. Let’s not get into the science part of it. Anyway, the amount of carbon in the atmosphere has fluctuated a lot over the years. So, the scientists saw that these carbon fluctuations altered the dates deduced using this method.
To find out the precise time, scientists then took the help of different methods such as the Tree-Ring method (dendrochronology), examination of volcanic eruptions, ice cores, sedimentary layering, cave deposits, etc. These methods used in unison with Carbon Dating helped them calibrate the dates.
The notation of whether the date is calibrated or not is as follows:
| Abbreviation (Usually used) | Calibration | Example |
|---|---|---|
| Upper case abbreviation ‘BC’ And/OR The word ‘cal’ | Calibrated | Uncalibrated date: 3000 bc calibrated to 3347 BC or 3347 cal BC |
| Lower case abbreviation ‘bc’(But, sometimes, Upper Case ‘BC’ is used too.) | Uncalibrated | 3000 bc |
What is BP?
The acronym ‘BP’ or ‘bp’ stands for ‘Before Present’ ~ ‘years before present’.
IMPORTANT: – The date in ‘Before Present’ is not really ‘the Present’. The ‘present’ in ‘BP’ is January 1, 1950.
(Since Carbon Dating was discovered in the 1940s. Also, the present time is never constant.)
Is BP the same as BC?
In the calendar marking system, BP is not the same as BC. BP is ‘Before Present’ while BC is ‘Before Christ’. According to the standard practices, the present is set to 1950 AD. Therefore, there is a difference of around 1950 years in a BC and BP year.
How do you convert BP to BC/AD or BCE/CE?
Here’s the simple formula to convert from BP to BC/AD or BCE/CE:
Example 1:
Convert 4000 BP to BC/AD or BCE/CE system.
4000 > 1950
4000 – 1949 = 2051 BC
Example 2:
Convert 150 BP to BC/AD or BCE/CE system.
150 < 1950
1950 – 150 = 1800 AD
The logic behind this formula: –
Example 1:
Convert 150 BP to BC/AD or BCE/CE system.
1950 – 150 = 1800
Since the result is positive, the result is –
150 BP = 1800 AD
This makes sense because the event happened in 1800 AD which happened 150 years before the present (1950)
Example 2:
Convert 4000 BP to BC/AD or BCE/CE system.
1950 – 4000 = -2050
Since the result is negative, we will subtract 1 from it. This is because there is no year 0. So, we have to count one year less as shown in Image 3.
-2050 -1 = -2051
So, our answer is 2051 BC.
4000 BP = 2051 BC.
Please note that this conversion is only valid for the years that happened on or before 1950 AD.
Why use BP and BC together?
When scientists use Carbon Dating to find out the date, the result is the age of the material as of today’s date. But, the date is not precise and needs further calibration. This date in BP is then converted to BC. So, it has become a common practice to mention both the carbon date and the calibrated date.
What is ka?
The acronym ‘ka’ is short for ‘kilo annum’ or ‘a thousand years’. ‘kyr’ also stands for ‘thousand years’ k- being the prefix denoting ‘Kilo’.
(Just how ‘Kilo’ refers to 1000 in other measurements.)
As per a Wikipedia entry, “ISO 80000-3 recommends usage of ka (for kilo annum), which avoids the implicit English bias of “year” by using a Latin root.”
This notation is generally used by people who have to deal with so old dates such as Geologists, Archeologists, Paleontologists, Anthropologists, etc.
For example, Late Stone Age is said to have occurred between 50 ka to 12 ka (50,000 and 12,000 years ago ~ BC 48000 to 1000 BC)
What is circa? (c. or ca.)
Circa is a Latin word that means ‘Around’ or ‘Approximately’. It is used to denote a date as a buffer. We know that the event happened around that date but are not sure exactly when.
Sometimes, you will see a date written as c. 300 B.C.E. That means the said event had happened approximately or around 300 years before the Common Era.
Here are some other Frequently Asked Questions about timelines:
Is it okay if we don’t use the notation?
It’s okay to drop the “AD” or “CE” when it’s not causing any confusion. But, it’s never okay to drop “BC” or “BCE”
For example,
- My friend Geeta was born in 1996.
- Julius Caesar was born in 100 BC.
How many BC years were there? What was the last BC year?
There are infinite numbers of BC years. Just like on the number line – the number before ‘0’ goes to negative infinity. So, what was the last BC year? Again, since the number is infinite, we cannot trace it back to the last BC year. It was perhaps when ‘time’ started – if there is any such thing. According to a study posted by NASA, “solar system settled into its current layout about 4.5 billion years ago”. So maybe we can take that as the last BC year.
What is the right word order & punctuation for the use of Calendar Notations?
| AD | Before the year | AD 1525 |
| BC | After the year | 5646 BC |
| CE | After the year | 2011 CE |
| BCE | After the year | 1134 BCE |
In which timeline are we living – AD, BC, BCE, or CE?
According to the Gregorian Calendar that we are following here, we are living in 2021 CE (or, AD 2021). Unless the notations are changed in the future, we will continue to live in ‘CE’ or ‘AD’ till the end.
What is the point of C.E and B.C.E, since it still determines common eras by the birth of Christ?
Why Have Some People Adopted BCE/CE?
Why do we still have BC-AD despite having BCE-CE?
In the book ‘Pondering the Passion’, Cunningham and Starr (1998) mentioned that “B.C.E./C.E. …do not presuppose faith in Christ and hence are more appropriate for interfaith dialog than the conventional B.C./A.D.”
Basically, BCE-CE is a more secular and less-Christianity-oriented name of BC-AD. The traditional BC-AD system makes the birth of Jesus Christ and thus, the Christian religion the center point of the history of mankind. Every event is marked with the reference to Christ’s birth.
It was later found that Jesus Christ was born in or before 4 BC. Therefore, the calculations of AD-BC are not really based on his correct birth period. So, even though the current calculating system of BC-AD remains constant, calling it ‘the common era’ instead of ‘birth of Jesus’ is accepted by many.
The political battle “AD-BC v/s BCE-CE” has been there ever since the new system began. While supporters say that “BCE-CE” is more inclusive and secular, opponents believe that it is offensive to Christians. The opponents also claim that it makes no difference since the reference point remains the same.
In the BC-AD system, BC stands for English words “Before Christ” while AD stands for Latin words “Anno Domini.” CE-BCE doesn’t constrain itself to one particular religion. Therefore, experts believe that the acceptance should be global.
Conclusion:
So, we are all living in AD 2021 which means 2021 years after the said birth of Jesus later to be named the Common Era. If there is any doubt, please contact us through the contact page or mail us at hello@agoodlibrary.com.
Also, as promised, the YouTube video with an even better explanation will be published tomorrow on our channel. Please refer to the schedule given in the sidebar (for desktop users, or below the article for mobile users) for the upcoming content on this topic.
