Iglesia Catedral de San Mateo As baptized people, we are committed to attending Mass on Sundays and the Feasts of Obligation, that is, the important feasts for our Christian life. "Hearing the whole Mass" implies being punctual, that is, arriving before the time the Mass begins. If for some reason we are late, it is advisable to wait until the next hour of mass, for better participation. The feasts of observance are important dates such as Christmas and Epiphany, Easter S