The Liturgical Year
Back to Miscellanea

The Sundays and weekdays of the major seasons of the year (Advent, Christmas, Lent, and Easter) are determined by their relationship to Christmas and Easter.

Ordinary time (i.e. "ordered time") refers to all other Sundays and weekdays. There are either 33 or 34 weeks of ordinary time, depending on the year, and they are divided into two parts of the liturgical year. Ordinary time begins when the Christmas season ends and continues until Ash Wednesday, then picks up again after Pentecost and continues until the first Sunday of Advent.

Here is a JavaScript program that generates the liturgical calendar for any given year.



Advent: Advent begins on the fourth Sunday before Christmas, and runs until December 24.

Christmas: The Christmas season lasts from Christmas until the Sunday after Epiphany, the Baptism of the Lord.

Lent: Lent begins on Ash Wednesday and ends with the Mass of the Lord's Supper on Holy Thursday.

Easter Triduum: The Easter Triduum begins with the evening celebration of the Mass of the Lord's Supper on Holy Thursday, and ends on Easter Sunday. These are the three holiest days of the Church year.

Easter: The Easter season consists of the fifty days between Easter and Pentecost.

Determining the date of Easter

Together, the Lenten season and the Easter season make up about a quarter of the entire year.

Ordinary Time: The first part of ordinary time starts with the Sunday after Epiphany -- which is always celebrated as the Feast of the Lord's Baptism -- and runs until Ash Wednesday.

Since the date of Easter varies from year to year, the first part of Ordinary Time can be as short as four weeks or as long as nine weeks.

The second part of ordinary time begins on the Monday after Pentecost and ends before the First Sunday of Advent.

If there are 34 ordinary weeks in the year, the numbering of the weeks picks up where it left off before Lent -- the week after Pentecost is the one that follows the last week celebrated before Lent.

If there are 33 ordinary weeks in the year, the first week that would (in a 34-week year) follow Pentecost is omitted.

"Based on actual events!"