well, religeously speaking, the jews and muslims don't use
our common year enumeration. year '0' (well, actually they started counting with '1'

) is a christian definition, but has generally been accepted in the western world.
to call it BC/AD might be offensive, but using BCE/CE only enforces "our" enumeration in other regions: year '0' is still defined by christians.
before changing the abbreviations, the english speaking world would better enforce the metric system