In the Western liturgical year, Lady Day is the traditional name in some English-speaking and Scandinavian countries of the Feast of the Annunciation, which is celebrated on 25 March, and 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.

The Feast of the Annunciation 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; however, if 25 March falls either in Holy Week or in Easter Week, the feast is postponed to the Monday after the Second Sunday of Easter.