BCE or B.C.E.

A somewhat recent term meaning Before Common Era that is often used instead of BC.

Some Christians frown upon the use of BCE instead of BC but it makes some since since the indications are that Jesus Christ was probably born, if born, several years before the year his birth is said to have occurred according to the history of Christianity.

The end of BC and thus the start of AD seems to have been at, or about, the time that the Sun seemed to rise in Pisces, which perhaps has something to do with the Christians using the Fish as a Symbol of Christianity.

Remember that there is no Year 0 since the Zero had not yet been invented, at least in Europe and the Middle East.