In the Roman Catholic Church, 1 January is a solemnity, the Feast of the Circumcision of Christ, honoring the Blessed Virgin Mary, the Mother of Jesus; it is a Holy Day of Obligation in most countries (Australia being a notable exception), thus the Church requires the attendance of all Catholics in such countries for Mass that day. However a vigil Mass may be held on the evening before a Holy Day; thus it has become customary to celebrate Mass on the evening of New Year's Eve. (New Year's Eve is a feast day honoring Pope Sylvester I in the Roman Catholic calendar, but it is not widely recognized in the United States.)