Beginning the Church's liturgical year, Advent (from, "ad-venire" in Latin or "to come to") is the season encompassing the four Sundays (and weekdays) leading up to the celebration of Christmas.
The Advent season is a time of preparation that directs our hearts and minds to Christ’s second coming at the end of time and to the anniversary of Our Lord’s birth on Christmas. From the earliest days of the Church, people have been fascinated by Jesus’ promise to come back. But the scripture readings during Advent tell us not to waste our time with predictions. Advent is not about speculation. Our Advent readings call us to be alert and ready, not weighted down and distracted by the cares of this world (Lk 21:34-36). Like Lent, the liturgical color for Advent is purple since both are seasons that prepare us for great feast days. Advent also includes an element of penance in the sense of preparing, quieting, and disciplining our hearts for the full joy of Christmas.
The rhythm of the liturgical seasons reflects the rhythm of life — with its celebrations of anniversaries and its seasons of quiet growth and maturing.
Ordinary Time, meaning ordered or numbered time, is celebrated in two segments: from the Monday following the Baptism of Our Lord up to Ash Wednesday; and from Pentecost Monday to the First Sunday of Advent. This makes it the largest season of the Liturgical Year.