The calendar (BCP, pp. 15-33) orders the liturgical year of the Episcopal Church by identifying two cycles of feasts and holy days-one dependent upon the movable date of Easter Day and the other dependent upon the fixed date of Christmas, Dec. 25. Easter Day is the first Sunday after the full moon that falls on or after Mar. 21. The sequence of all Sundays in the church year is based on the date of Easter. Tables and rules for finding the date of Easter Day, and other movable feasts and holy days are provided by the BCP, pp. 880-885. The date of Easter determines the beginning of the season of Lent on Ash Wednesday and the date of Pentecost on the fiftieth day of the Easter season. The Sundays of Advent are always the four Sundays before Christmas Day. The church year begins on the first Sunday of Advent. The calendar also identifies and provides directions concerning the precedence and observance of principal feasts, Sundays, holy days (including Feasts of our Lord, other major feasts, and fasts), Days of Special Devotion, and Days of Optional Observance. The calendar lists dates for celebration of major feasts and lesser feasts by month and date. Appropriate Sunday Letters and Golden Numbers are also provided. (see BCP, pp. 880-881). The calendar also lists the titles of the seasons, Sundays, and major holy days observed in the Episcopal Church throughout the church year, including Advent season, Christmas season, Epiphany season, Lenten season, Holy Week, Easter season, the season after Pentecost, holy days, and National Days.