Paschal Triduum
The Feast of the Annunciation, contemporarily the Solemnity of the Annunciation, and also called Lady Day, the Feast of the Incarnation ('), or Conceptio Christi ('), commemorates the visit of the archangel Gabriel to the Virgin Mary, during which he informed her that she would be the mother of Jesus Christ, the Son of God. It is celebrated on 25 March each year. In the Roman Catholic Church, when 25 March falls during the Paschal Triduum, it is transferred forward to the first suitable day during Eastertide. In Eastern Orthodoxy and Eastern Catholicism, it is never transferred, even if it falls on Pascha (Easter). The concurrence of these two feasts is called "Kyriopascha".