ante diem vii kalendas februarias

Sementivae or Paganalia (day ?) -- Sementivae was a festival of sowing which was actually a moveable feast (although I'm not sure of the moveability criteria; I'm guessing that the first day falls between January 24 and 26). By Ovid's time it appears to have been coincident with Paganalia, which also obviously has some rural aspect to it. It appears to have been a two-day festival with an interval of seven days between (corrections on this welcome ... my sources seem muddled on this one)

66 A.D. -- perihelion of what would eventually be called Halley's comet (possibly mentioned in Josephus; less possibly mentioned in Suetonius)

97 A.D. -- martyrdom of Timothy

1721 -- death of Pierre Daniel Huet (editor of the Delphi Classics)