The Solemnity of the Immaculate Conception, also called Immaculate Conception Day, celebrates the sinless lifespan and Immaculate Conception of the Virgin Mary, celebrated on December 8, nine months before the feast of the Nativity of Mary, celebrated on September 8. It is one of the most important Marian feasts in the liturgical calendar of the Roman Catholic Church celebrated worldwide. By Pontifical decree, it is the patronal feast day of Argentina, Brazil, Italy, Korea, Nicaragua, Paraguay, the Philippines, Spain, the United States, and Uruguay. By royal decree, it is designated as the day honoring the patroness of Portugal. It is celebrated by the Roman Catholic Church and some select Protestant Christian denominations. Since 1953, the Pope visits the Column of the Immaculate Conception in the Piazza di Spagna to offer expiatory prayers commemorating the solemn event. Source: Duckduckgo API