For those who follow St. Luke’s on Facebook (the parish where I currently serve), we began posting images or quotes associated with particular saints this summer. We do this to help us better know the saints. This is also part of the reason that led to the series, Our Saints and Intercessors, that Fr. Jeff is doing.
One might wonder how we choose the saints that are posted on our parish Facebook page. The simple answer is that we do not choose which saints are reflected in the posts. We are following the church’s daily calendar. When we post an image or a quote from a particular saint, it is their day on the liturgical calendar.
In general terms, we call the day assigned to a particular saint their “feast day.” However, there are different levels of “feast days.” There are feasts (all of which are obligatory), obligatory memorials, and optional memorials.
When it is the feast day of a saint, there are special prayers that can be used at Mass for the Collect (opening prayer), Offertory Prayer (prayer over the gifts), and the Prayer After Communion. There can also be special readings associated with a saint’s feast day.
With rare exception, when a feast day is celebrated on Sunday, the saint prayers and readings are NOT used as the Sunday readings and prayers take precedence. During the week, when a saint day is a feast, the readings and prayers must be used for daily Mass. When it is an obligatory memorial, the prayers must be used while the readings may or may not change. For optional memorials, it is the discretion of the priest who is presiding at Mass whether or not to use the prayers or readings associated with the saints.
You might wonder what determines whether a saint’s feast day is a feast, obligatory memorial, or an optional memorial. It is not a matter of how “powerful” the saint is. Rather, it is based on how well they are known, locally or worldwide. For instance, on the universal calendar, October 19th, is an optional memorial for St. Isaac Jogues and his companions, known as the North American martyrs. For us in the United States, since they were martyred between Albany and Canada in the 17th century, their feast day is an obligatory memorial. Our own parish saint, St. Luke is a feast as he is known to all as the writer of the gospel that bears his name and the Acts of the Apostles.
If you would like to learn more about saints on their feast day, a great resource is saintoftheday.org.