Solemnity of the Immaculate Conception is a usually a Holy Day of Obligation in the Diocese of Phoenix and refers to the special way the Blessed Virgin Mary was conceived. However, this year, the Solemnity falls on a Sunday, and therefore is moved to Monday, December 9th. It is not a Holy Day of Obligation this year. The dogma of the Immaculate Conception was proclaimed by Pope Pius IX in 1854:
The most Blessed Virgin Mary was, from the first moment of her conception, by a singular grace and privilege of almighty God and by virtue of the merits of Jesus Christ, Saviour of the human race, preserved immune from all stain of original sin.
Visit dphx.org/parishes to find Mass times at your parish!