It begins on the fourth Sunday before Christmas Day, which is the Sunday nearest November 30, and ends on Christmas Eve (Dec 24). If Christmas Eve is a Sunday, it is counted as the fourth Sunday of Advent, with Christmas Eve proper beginning at sundown.
The Meaning of "Advent"
The word Advent means "coming" or "arrival." The focus of the entire season is preparation to celebrate the birth of Jesus the Christ in his First Advent, and the anticipation of the return of Christ the King in his Second Advent. Thus, Advent is far more than simply marking a 2,000-year-old event in history. It is celebrating a truth about God, the revelation of God in Christ whereby all of creation might be reconciled to God. That is a process in which we now participate, and the consummation of which we anticipate. Scripture reading for Advent will reflect this emphasis on the Second Advent, including themes of accountability for faithfulness at His coming, judgment on sin, and the hope of eternal life.
In this double focus on past and future, Advent also symbolizes the spiritual journey of individuals and a congregation, as they affirm that Christ has come, that He is present in the world today, and that He will come again in power. That acknowledgment provides a basis for Kingdom ethics, for holy living arising from a profound sense that we live "between the times" and are called to be faithful stewards of what is entrusted to us as God’s people. So, as the church celebrates God’s breaking into history via the Incarnation, and anticipates a future consummation to that history for which "all creation is groaning awaiting its redemption," it also confesses its own responsibility as a people commissioned to "love the Lord your God with all your heart" and to "love your neighbor as yourself."