when did we go from bc to ad
Anno Domini This calendar era is based on the traditionally reckoned year of the conception or birth of Jesus of Nazareth, with AD counting years from the start of this epoch, and BC denoting years before the start of the era. There is no year zero in this scheme, so the year AD 1 immediately follows the year 1 BC. This dating system was devised in 525 by Dionysius Exiguus of Scythia Minor, but was not widely used until after 800.[9][10]
New Testament The original texts were written in the first century of the Christian Era, in Greek, which was the common language of the Eastern Mediterranean from the conquests of Alexander the Great (335–323 BC) until the Muslim conquests in the 7th century AD. All the works that eventually became incorporated into the New Testament are believed to have been written no later than around 120 AD.[3][4][better source needed] John A. T. Robinson, Dan Wallace, and William F. Albright dated all the books of the New Testament before 70 AD.[5] Others give a final date of 80 AD,[6] or at 96 AD.[7]