I think they using muslem dates.
Before Common Era, i.e. BC. This is terminology that seems to have been adopted in the last 25 years and it is used everywhere now.
It means the same thing, but in secular terms and it’s not a Muslim thing.
“What the **** does common era mean?”
Before Christ.
If you accept the fact that the ‘Common Era” begins with the old date of .B.C. then BCE is just a way of saying it without saying it.