Recurrence pattern: Every year on the first Sunday of Advent, between November 27 and December 3.

The First Sunday of Advent marks the beginning of the Advent season, occurring on the fourth Sunday before Christmas. This day is observed by Christians as a time of anticipation and reflection in preparation for the celebration of Jesus Christ's birth and the expectation of His return. It is characterized by the lighting of the first candle on an Advent wreath, often purple, symbolizing hope. Customs include prayers, readings, and singing traditional carols that reflect Advent themes. The day also serves as a reminder of the virtues Christ brings to the world, such as hope, love, joy, and peace, which are highlighted in subsequent Sundays of Advent. The observance of Advent has historical roots that evolved over centuries within the Christian liturgical calendar.