All Saints’ Day is a Holy Day of Obligation celebrated by the liturgical Church on November 1st. We turn to the saints, those known and unknown by the Church, as guides and models of holiness on this day. 

All Saints Day originated in May 609, when Pope Boniface IV dedicated the Pantheon in Rome to the Blessed Virgin Mary. In the 8th century, Pope Gregory III changed the date to November 1 when he dedicated a chapel at the Vatican in honor of all the saints, and Pope Gregory IV later extended this celebration of all saints to the universal church.