Feast Day: December 8
Solemnity of the Immaculate Conception of the Blessed Virgin Mary, defined ex cathedra by Blessed Pope Pius IX in Ineffabilis Deus (1854). Holyday of Obligation. Patronal Feastday of the United States of America (USCCB Liturgical Calendar 2026).
Saints Commemorated on December 8
From the USCCB 2026 Liturgical Calendar.