Rejoice!

Gaudate Sunday falls on the third Sunday of Advent.  It takes its name from the first word of the Introit.

"Gaudete in Domino semper: iterum dico, gaudete. Modestia vestra nota sit omnibus hominibus: Dominus enim prope est. Nihil solliciti sitis: sed in omni oratione petitiones vestræ innotescant apud Deum." Phil. 4:4-6

"Rejoice in the Lord always; again, I say, rejoice.  Let your modesty be known to all men. The Lord is nigh.  Be nothing solicitous; but in every thing, by prayer and supplication, with thanksgiving, let your petitions be made known to God."

Gaudete Sunday is the counterpart to Lætare Sunday in Lent.  Falling as it does at the half-way-point of Advent, the penitential season of expectation leading up to Christmas, Gaudate Sunday provides a moment of relief from the austerities of the fast, thus the liturgical colour of rose replaces the penitential violet.