In The Episcopal Church, as in some other denominations, we follow a Calendar for the Church Year made up of various seasons centered around Christmas and Easter. Each Sunday, our readings and certain prayers come from a particular Sunday within each season.
There are a few days, listed in The Book of Common Prayer, that take precedence if they fall on a Sunday.
There is another kind of celebration that can take precedence on a Sunday, and that's the feast day for the Dedication of a Church as well as the feast day of the the patron (or title) of a particular Church, whether on the day or transferred to a Sunday (as long as this isn't a Sunday in Advent, Lent, or Easter).
Here is an example of what that looks like. Currently, as I am shooting the video, I am serving at St. Michael's Episcopal Church. As we are approaching the end of September in 2020, we are taking the feast day of St. Michael and All Angels and moving it to the closest Sunday, two days prior. Instead of celebrating the 17th Sunday after Pentecost that day, we will celebrate St. Michael and All Angels.
Celebrating the feast day for each of our worshiping communities' patron saints or titles is important. We choose those names for our communities for a reason, generally because we feel some affection or affiliation with that saint or title. Celebrating the feast day of that saint or title reminds us, in word and prayer, who that person was and, thus, who we strive to be as well. Thanks to the rubrics set up at the start of The Book of Common Prayer, we can all do that together in our weekly Sunday worship.