In the Christian calendar, which follows the life of Jesus, the period of preparation before his birth on Christmas Day. It begins four Sundays before Christmas on Advent Sunday; the date varies depending on which day of the week Christmas falls.
On the first Advent Sunday, candles are lit in churches. Some churches have an Advent Wreath, a circular wreath of holly with four candles round the edge and a fifth one in the centre. The candles are lit one by one as the weeks pass, until the central candle is lit on Christmas Day. Many families will have Advent calendars with little doors to open each day leading up to Christmas. Christmas scenes are depicted and the last door is opened on Christmas Day.
During Advent, the altar cloth will be changed from the regular green to purple, representing a time of preparation and penitence. Special Advent hymns are sung as Christians celebrate the approach of Jesus' birth. Near Christmas, carol services are held and young children, in many schools, perform nativity plays, recalling the birth of Jesus.
Formerly, Advent was sometimes kept almost as strictly as Lent, public amusements and festivities being prohibited and fasts observed. Since the 6th century it has been the start of the ecclesiastical year, except in the Orthodox Church, where it begins on the first day of September (the Byzantine civil New Year).