In the Catholic Church, Holy Days of Obligation are the days on which the faithful are obliged to participate in the Mass. They also abstain from unnecessary works, "which hinder the worship to be rendered to God, the joy proper to the Lord’s day, or the suitable relaxation of mind and body." (Canon 1247 of the Code of Canon Law).

All Sundays are obligatory for the faithful to participate in the Mass. Mass times for Sundays and Holy Days can be found in the bulletin.