Ash Wednesday, in the Protestant Christian church, the first day of Lent, occurring 40 days before Easter. Ash Wednesday is a solemn reminder of human mortality and the need for reconciliation with God and marks the beginning of the penitential Lenten season. It is commonly observed with ashes and fasting.
Why it is calculated with 40 days? In the 7th century, 4 days were added before the first Sunday in Lent in order to establish 40 fasting days, in imitation of Jesus Christ’s fast in the desert.It was the practice in Rome for penitents and grievous sinners to begin their period of public penance on the first day of Lent in preparation for their restoration to the sacrament of the Eucharist.