The Catholic liturgical calendar marks days and seasons that are significant in the Catholic faith. It begins at the beginning of December, or end of November and ends on the feast of Christ the King. The calendar also instructs followers about which readings to use for each day.
The liturgical calendar lists the feasts, memorials and solemnities each week. A small colored cross shows which vestments the priest wears during each observance.
Advent, which is the first season of the calendar, includes four Sundays. The Christmas season follows and includes the celebration of the birth of Christ, as well as the Feast of the Holy Family, the Feast of the Mother of God and Epiphany. Following Christmas Ordinary Time, this season lasts until the beginning of Lent. Lent begins on Ash Wednesday and continues until the Thursday before Good Friday, followed by Triduum, which lasts for three days, and then Easter. Pentecost follows Easter, and then Ordinary Time fills the remainder of the calendar until the beginning of the next cycle.
The liturgical calendar has a cycle of three years. During the first cycle, usually denoted by an A, Matthew is the primary source of readings. The second cycle uses Mark as the primary source of readings, and in the third cycle Luke is used.
In addition to the universal liturgical calendar, churches may use regional or national liturgical calendars. These calendars incorporate holidays celebrated in specific areas of the world or regional saints.