Traditional end of the Roman year (followed by a period of intercalation)
Terminalia -- a festival in honour of Terminus, the divinity who presided over boundaries. In Rome itself, Terminus had a shrine within the Temple of Jupiter beneath an opening in the roof because, it is said, when they were building the Temple of Jupiter, Terminus refused to move. What happened in the city is unclear, but the rustic version of the festival involved the following: at boundary stones, farmer families would gather and build a turf altar; a fire would be built and one of the younger members of the family would throw grain in the fire three times. Others offered other things like honeycombs and wine, then a sheep or pig would be sacrificed and a feast would follow.
155 A.D. -- martyrdom of Polycarp at Smyrna
303 A.D. -- "Great Persecution" of Diocletian begins in Nicomedia
303 A.D. -- martyrdom of Serenus the Gardener at Sirmium