In the Episcopal Church, many elements of the liturgy are relatively stable from week to week–the Lord’s Prayer, for example, the Eucharist, the creed, the blessing, etc. But you’ll notice that every Sunday the readings change, and so do certain prayers. How are these selected?
Well, get ready for some complicated liturgical calculations.
One: The Lectionary
The first piece of the equation you need to know is the Lectionary.
The Episcopal Church and many other denominations use the Revised Common Lectionary, an ordered system for scripture readings throughout the year for Sundays and certain Holy Days (Easter, for example, and Christmas). Every Sunday, and each of these feast days, has an appointed Psalm and readings from the Old Testament, the New Testament, and one of the Gospels. The lectionary is divided into a three-year cycle (Years A, B, and C). Each cycle begins on the first Sunday of Advent and is intended to reflect the life of Jesus, by retelling his birth (Christmas), death and resurrection (Good Friday and Easter), and other stories and actions throughout his life.
The Revised Common Lectionary was compiled by the Consultation on Common Texts, which includes representatives from Lutheran, Methodist, Catholic, Presbyterian, Unitarian, and other denominations. This group was established in 1960, and officially released the RCL in 1994.
Plus Two: The Proper
So, determining Sunday’s readings is the easy part. Next is understanding what a Proper is.
You’ve probably seen “Proper 13” or something similar on the cover of the bulletin or in the prayer book, but even many lifelong Episcopalians don’t really know what it means.
It’s relatively straightforward: Each Sunday has a different Proper, which is made up of the collects (prayers), prefaces, and readings appointed for that week. The word comes from the Latin, proprium, which means “own” or “particular.”
For example, here is a collect from a recent Sunday:
Grant us, Lord, not to be anxious about earthly things, but to
love things heavenly; and even now, while we are placed among
things that are passing away, to hold fast to those that shall
endure; through Jesus Christ our Lord, who lives and reigns
with you and the Holy Spirit, one God, for ever and ever. Amen.
Collect for Proper 20, BCP p. 234
The preface is a series of sentences said before the retelling of salvation history during Holy Eucharist. This is a preface used on some Sundays:
For you are the source of light and life, you made us in your image, and called us to new life in Jesus Christ our Lord.
Preface of the Lord’s Day: Of God the Father, BCP 377
Finally, each Sunday has the readings appointed in the lectionary, as well as a different set of readings for the following days of the week, Monday through Saturday. All this is called the Proper.
Plus Three: The Date of Easter
The major seasons, such Advent and Lent, are always about the same length, so the readings, collects, and prefaces are stable from year to year. Lent is 40 days plus six Sundays, Easter season lasts 50 days, and Advent always begins four Sundays before Christmas.
But determining the readings between Pentecost, which falls 50 days after Easter, and Advent gets a little more complicated. This is because the date of Easter is variable, and so the number of weeks between Pentecost and Advent varies from year to year.
Easter always falls on the Sunday after the first full moon that occurs on or after March 21, the spring equinox. March 21 is fixed according to an ancient ecclesiastical computation, and is not always the same as the astronomical spring equinox. (If you really want to get into the weeds, check out page 880 of The Book of Common Prayer, where you can learn how to find the date of Easter in any year, using something called the Golden Number and the Sunday Letter. There are about six pages of charts to help you out. Anyway, most of us just google it.)
Many Propers are named according to the liturgical season or the observance of a feast day (i.e., the Third Sunday in Lent, All Saints’ Day, etc.) During the season between Pentecost and Advent, sometimes called Ordinary Time, the Episcopal Church uses numbered Propers.
There are a total of 29 Propers, and, basically, you work backwards. Proper 29 is always the Sunday closest to November 23 (the Sunday before the first Sunday of Advent), Proper 28 is the Sunday closest to November 16, and so on. If Easter occurs on April 25, the latest possible date, Pentecost will also come later in the year and you won’t need Propers 1 through 5. If Easter is near March 21, you’ll start closer to Proper 1 and go from there.
Equals Your Readings
Once you know your Proper, you can consult The Book of Common Prayer for the collect and preface for Sunday, as well as the readings for the other days of the week. Unlike the Sunday readings, the readings for the rest of the week are on a two-year cycle.
Now you’ve got everything you need to know to determine the readings every day of the year. If you’re still confused, consult your local priest, sacristan, or verger (or you can always visit lectionarypage.net). The Vanderbilt Divinity School Library also has a useful page with information about the lectionary and answers to many of your questions.