The Christian season of Lent begins today, 40 days before Easter (not counting Sundays). Many Christians attend church services on Ash Wednesday to receive ashes on their foreheads in the sign of the cross. (Ashes are a symbol of penance in the Old Testament and in pagan antiquity.) In the Roman Catholic Church, Ash Wednesday is a day of fasting. In the sixth century, Christians who had committed grave faults were obliged to do public penance. On Ash Wednesday, they donned a hair shirt (which they wore for 40 days), and the local bishop blessed them and sprinkled them with ashes. Then, while others recited the Seven Penitential Psalms, the penitents were turned out of the holy place. They could not enter the church again until Maundy Thursday (the Thursday before Easter), when they received absolution.