since christianity as a religion, is professed by only about 25% of the worlds population, i think it is rude to insist on BC/AD for dates. its enough that common calendars start with a date close to the year jesus was born.
Before the Common Era and Common Era, are simple, and non religious based.
BP (before the present) is nice too. i don't think it is necessary for us to go around saying 2002 AD-latin for 'year of the lord' -- its certainly not the year of the lord for muslems, or for budists, or for shinto beleivers, many who, for business purposes, are forced into using western date notation.
curiously, the japanese still use their old style of dating for many purposes.. my brother inlaw was born 18/8/3 (the eighteenth day of the eight month, (august) in the third year of the emperors reign.)-- the Japanese didn't have proper name for months, they just numbered them, so they found it very easy to convert to western numbers, even to a point of starting with january, and not with the old lunar new year used by most of that part of the world. they manage even though the western calendar has a slightly different number of day to a month. but legal dates, like birthdays, wedding, deaths, are still measured by the year of the emperor.
(my neice was born 15/8/3-- and he father teases her that she is older than he is by three days. -new emperor.)
