A title still commonly used in Ireland and elsewhere for the feast of the Assumption, August 15,. "Day of Mary Mother of God" is the primitive title for the feast. The old Armenian calendar (5th century) carried it for the date corresponding to August 15, under the title of the "Annunciation of the Mother of God" referring to the decree of the Council of Ephesus (c.431) which declared as a dogma of faith that Mary was truly the Mother of God.