ante diem iii nonas decembres

Possible date for rites in honour of the bona dea: essentially private rituals for Roman women only held in the house of a consul or praetor and attended by the Vestal Virgins and assorted upper class types. The actual date does not appear to have been 'fixed' and, of course, this ritual was 'crashed' by P. Clodius (dressed as a woman) in 62 B.C. with all sorts of nasty spinoffs, not least of which was the Julius Caesar's divorce from his wife Pompeia.

313 A.D. -- death of the retired emperor Diocletian