Glad I could help, sunray. Even though it didn't make any difference to the puzzle, it can be annoying if you're still wondering about something in it!
You are right, although ann comes from annate, it is not actualy noted as an abbreviation. Colloquial I guess, and appropriate for today's date! (being Scots like myself)
Thanks, Lumen. I wondered if you had an older Chambers with 'ann' given as an abbreviation. I checked 'Ad Fin' when I did the crossword - I remembered when I re-read it today!