Abbreviation for "common era." This abbreviation is a non-religious designation used in place of the traditional AD for years of the common or Christian era. Years of the common era are supposed to be counted from the birth of Jesus of Nazareth, founder of the Christian religion. However, the year-numbering system was not established until more than 500 years later. It is based on calculations of the priest and scholar Dionysius Exiguus placing Jesus's birth in the Roman year 753 AUC. Dionysius knew he had incomplete information, and there is evidence that he picked this particular date to simplify the calculation of the date of Easter. According to the Biblical account, Jesus was born several years before the death of Herod the Great, who died, we now know, in 750 AUC (4 BC). Thus the calculation of the common era is off by 6 or 7 years at least. In the conventional use of the common era system, there is no year 0 and the year prior to 1 CE is designated 1 BCE (or 1 BC). In astronomy, however, it simplifies calculations to define the year 0 CE = 1 BC and to apply negative numbers to earlier years. Thus Herod died in -3 CE, and, in general, -n CE is the year more commonly called'n + 1 BC