The seasons of the Catholic Church’s liturgical year recall the different events in Jesus’ life.
The year begins on the first Sunday of Advent, always four Sundays before Christmas. The Advent season is one of preparation for the coming of Jesus, both as the Christ-child of Christmas and his final coming. The Advent season ends on Christmas Eve.
The Christmas season follows and is celebrated until the Feast of the Baptism of Christ, which is the first Sunday after Epiphany, Jan. 6.
Ordinary time occurs twice within the liturgical calendar. The first begins immediately after the Christmas season ends and runs through the day before Ash Wednesday. The second period of ordinary time begins on the Monday after Pentecost and extends to Advent.
Lent is a time of penance and sacrifice in preparation for Easter. It begins on Ash Wednesday and lasts for 40 days (the Sundays of Lent are not included).
Easter celebrates Jesus’ resurrection from the dead. The date varies from year to year; it is the first Sunday following the first full moon of spring (which begins March 21). The season ends with Pentecost, the 50th day of the season.