Religious event
The publicly-claimed ascension date of the Bloodrose Lady of Ravens, replacing the previous deity of death.
Though no documents or other methods of researching exist to confirm the claims of the Church of the Bloodrose Raven, the deity herself and her servants are the most active in the world, and show no recalcitrance about answering questions on a variety of topics beyond even the Lady's origination as a mortal. There are little-to-no reasons to doubt their direct testimony regarding the origins of the deity.