There are dozens of St. Sylvesters, and one of them was Pope (314-335). His feast day is December 31st.
Everyday is a spiritual day for Catholics, as everyday is a saint's feast day. December 31 is the feast day of St. Sylvester I. However, January 1st is a major feast day for Catholics - the feast of Mary, the Mother of God. It is a Holy Day of Obligation.
Simon shares October 26 as a feast day with St. Jude.
St. Francis of Assisi's feast day is on October 4. The feast day of St. Francis is on October 4.
March 7 is the feast day of St. Perpetua.
November 3 is the feast day of St. Hubert.
January 2 is St. Basil's feast day.
The feast day of St. Brice is November 13.
St. Lukes' feast day is on October 18
St. Ava's feast day is April 29.
St. Monica's Feast Day is August 27.
October 13th is the feast day of St. Edward the Confessor.
St. Linda (St. Ermelinda)'s feast day is October 29.