AD stands for the Latin phrase: Anno Domini, the year of our lord.
It is used to indicate which part of the timeline is being dated on the Gregorian calendar in years.
The creators of the Gregorian calendar felt that the most important marker in earth’s history was the coming of Jesus Christ. The term AD was used to begin this turning point in earth’s history. The year that the creators of this new calendar marked the 1AD was the year that they thought Jesus was born. Upon further study, biblical historians realized that the makers of the Gregorian calendar were a little off in their date and found that Jesus Christ was actually born about four years prior in what would be termed 4 BC.
This may bring one to the next question, “What does BC stand for?” The acronym BC means simply, “Before Christ.” Some have mistakenly defined AD as “after death,” as they imply that it relates to time after the death of Jesus. This is a common misconception.
Astronomers in the 1500s were hoping to keep a more accurate measure of the length of the year. They realized that it took more closely to 365.25 days for the earth to revolve around the sun. Therefore in 1580, the Gregorian calendar was introduced with the notion that every four years, that calendar year would need to have an extra day. This is what we call a “leap year.” Although the main astronomer who created the framework was an Italian scientist named Luigi Lilio, the calendar was named after the pope of that time, pope Gregory XIII.
The years in the Gregorian calendar are go forward in the term AD and backward in the term BC. To help better understand this in numerical terms, it is similar to a number line where all the numbers running positive to the right would be AD and those that are negative to the left would be BC. The only difference is that in the number line of historical dates there is no year zero. It goes from 1 BC directly to 1 AD.
While most of the world adheres to this method of dating, some have introduced a different label to identify years in history. The acronyms BCE and CE have more recently been utilized among historians. The term CE is defined as the, “Common Era.” In like manner BCE is defined as “Before the Common Era.” BCE is synonymous with BC. Likewise, CE is synonymous with AD. There is no difference in regard to calendar year. This method of labeling years was introduced as a more secular means of dating history. The Gregorian calendar is often called the “Christian calendar” as it is centered in the birth of Jesus.
In His service,