Catholics have the opportunity to go to Mass 7 days a week. The Catholic Church is open 7/365, not just one day a week like the protestant denominations Saturday is still the Sabbath, Sunday is the Lord's day Biblical references to happenings on Sunday, the first day of the week...1.Jesus Christ rose from the dead on Sunday, Lk 24:1-12 2.he Catholic Church is open 7/365, not just one day a week like the protestant denominations Saturday is still the Sabbath, Sunday is the Lord's day Biblical references to happenings on Sunday, the first day of the week... 1.