The term anno Domini is Medieval Latin and means "in the year of the Lord"  but is often presented using "our Lord" instead of "the Lord",   taken from the full original phrase " anno Domini nostri Jesu Christi ", which translates to "in the year of our Lord Jesus Christ". This calendar era is based on the traditionally reckoned year of the conception or birth of Jesus, with AD counting years from the start of this epoch and BC denoting years before the start of the era. This dating system was devised in by Dionysius Exiguus of Scythia Minor , but was not widely used until after It is often directly contrasted to the more ancient, Anno Mundi AM conferring "in the years of the world" which recounts the ages based on Biblical tradition beginning with the Creation account. To this day, it is firmly observed through virtually all Jewish religious sources, some minor non-Jewish orthodox societies, and is a reference in many aged and restituted manuscripts. The Gregorian calendar is the most widely used calendar in the world today.
What Is the Meaning of AD?
terminology - Why use BCE/CE instead of BC/AD? - English Language & Usage Stack Exchange
As abbreviations for Before the Common Era BCE and Common Era CE , they do not specifically privilege Christianity the criticism of using "BC" and "AD" and instead simply make reference to the fact that we are living in an era shared in common between Christianity and other religions—though Christianity and Judaism are the two religions usually in mind. Here are the facts. The tradition in the West is to base the count of our years around the alleged time when Jesus would have been born. Every year since his birth is "A. Every year before his birth, counting backward is "B. C," or "Before Christ.
Should We Use A.D. or C.E.?
Two such calendar eras have seen notable use historically:. While differences in biblical interpretation or in calculation methodology can produce some differences in the creation date, most results fall relatively close to one of these two dominant models. The primary reason for the disparity seems to lie in which underlying biblical text is chosen roughly BC based on the Greek Septuagint text, about BC based on the Hebrew Masoretic text. Most of the 1,year difference resides in numerical discrepancies in the genealogies of the two versions of the Book of Genesis.
The initials BP or bp and rarely B. While BP is also used generally as an imprecise estimate of an age of an object or event, the use of it in science was made necessary by the quirks of the radiocarbon methodology. Radiocarbon dating was invented in the late 's, and within a few decades, it was discovered that while the dates retrieved from the method have a sound, repeatable progression, they are not a one-to-one match with calendar years.