In our daily lives we keep track of our activities and special events with a calendar. The church throughout the centuries has also “kept track” of days and seasons and commemorating special occasions with a calendar.
The Christian church has continued to follow the example set in the Old Testament of structuring the year around the marvelous acts of salvation that God completed for us in his Son, Christ. We call this structure the Church Year.
The church year calendar is organized into three sections: Sundays and seasons, feasts and festivals, and commemorations. The seasons of the church year are marked by certain liturgical colors. More Info....
Found here are the Sundays and seasons in the cycles of the Church’s liturgical calendar: Christmas/Epiphany, Good Friday/Easter, and Pentecost, followed by the Time of the Church.