The Roman Missal: Proper of Saints, November 29 to January 31 (English) 15

1[December 20. Vigil of St Thomas, Apostle.]

2[Mass.—Ego autem sicut oliva, as in the Common, page i. with Commemoration of the Feria. But if this Vigil happens on an Ember Day, it is only commemorated in the Mass of the Ember Day.]