1) AD counterpart 2) PC dating letters 3) Chemistry degree 4) Dating inits 5) Dating letters 6) Early date identifier 7) Engineering degree 8) Initials for pre-AD period 9) Letters after a long-ago date 10) Letters after old dates 11) Letters after some dates 12) Letters from an old date 13) Letters in an old date Found on https://www.crosswordclues.com/clue/bce