The Solemnity of the Immaculate Conception is on December 8 – it is a Holy Day of Obligation.
Mass times at IHM are at 8:30 a.m. and 5:30 p.m.
The Catholic Church celebrates the belief that the Virgin Mary was conceived free from all stain of original sin so as to be a fitting
mother for the Son of God.
Her Immaculate Conception is universally celebrated on December 8, nine months before the feast of the Nativity of Mary, which is celebrated on September 8.
The web site below provides a lot of information on the doctrine of the Immaculate Conception: