In the Western liturgical year, Lady Day is the common name in some English-speaking and Scandinavian countries[clarification needed] of the Feast of the Annunciation, celebrated on 25 March to commemorate the annunciation of the archangel Gabriel to the Virgin Mary that she would bear Jesus Christ, the Son of God.

The commemorated event is known in the 1549 prayer book of Edward VI and the 1662 Book of Common Prayer as "The Annunciation of the (Blessed) Virgin Mary" but more accurately (as in the modern Calendar of the Church of England) termed "The Annunciation of our Lord to the Blessed Virgin Mary".

The day commemorates the tradition of archangel Gabriel's announcement to Mary that she would give birth to the Christ.

[3][4][better source needed] Two examples in liturgical Christianity of the importance attached to the Annunciation are the Angelus prayer and, especially in Roman Catholicism, the event's position as the first Joyful Mystery of the Dominican Rosary.

(The date is significant in some of the works of Thomas Hardy, such as Tess of the d'Urbervilles and Far from the Madding Crowd, and is discussed in his 1884 essay "The Dorset Farm Labourer").