Ash Wednesday takes place 46 days before Easter Sunday, and is chiefly observed by Catholics, although many other Christians observe it too. This day is one of the most popular and important holy days in the liturgical calendar. It opens Lent, a season of fasting and prayer.
During some Ash Wednesday services, the minister will lightly rub the sign of the cross with ashes onto the foreheads of worshipers. The use of ashes as a sign of mortality and repentance has a long history in Jewish and Christian worship. Historically, ashes signified purification and sorrow for sins.