There are 20 or more saints celebrated every day of the year.
The memorial of St. Lucy of Syracuse is celebrated on December 13.
Most feast days are celebrated with a Mass in honor of that saint. If you want to know about local customs, you need to be more specific, as in, "How is St. David's feast day celebrated in Wales?"
Saint Andrew's Day is the 30th of November. However, every day of the month there are 20 or more saints with feast days.
The feast of Saint Patrick is celebrated on March 17.
St. Sargis Day is celebrated 63 days before Easter, on a Saturday falling sometime between Jan. 18 and Feb. 23
Their death is not celebrated, their entrance into Heaven is celebrated.
All Saint's Day is November 1st, but the list of Saints that have their feast days celebrated in the month of November are on this website in the related links below.
Which Saint Ignatius? There are several.
Saint Stephen.
You do not mention which Saint Thomas you are referring to. There are several. Saints days are days set aside by the Church to commemorate the lives of those special people who gave their lives to God by serving His Church on earth.
Easter, Good Friday,Pentecost, Christmas and Twelfth Night ( Epiphany) are celebrated to some extent by almost all Christians. The Catholics have many other feast days and Saint's days of varying importance.
Saint Nicholas Day is celebrated world-wide on December 6.