What do bp, bc, bce, ad, ce, and cal mean?

BC - BCE and AD - CE terms, with BP

In almost all archaeology books and articles the authors use dates. Seeing ‘bp’, or ‘BP’, or ‘BC’ is common, and they are often used together. So, what’s the difference between them, and why use both? AD, ad, CE ‘AD’ means Anno Domini. This is the Christian era in the Gregorian calendar, starting from 1 AD … Read more