This year, Ash Wednesday falls on March 1, 2017. It marks the start of Lent, a 40-day liturgical period of prayer and fasting or abstinence. On that day we will see many people walk around the street with a cross marked on their forehead. But, what does that really mean? Why do most Christians leave the ashes on until the end of the day? Here are 6 fast facts to explain it better.

1) Ash Wednesday occurs 46 days before Easter. It’s the beginning of Lent, which represents the 40 days Jesus spent fasting in the dessert, where he endured temptation by Satan. This is a period of prayer and fasting. Of the 46 days until Easter, six are Sundays. Sundays are not included in the fasting period and are instead "feast" days during Lent.

2) The distribution of ashes comes from a devotional imitation of the practice observed in the case of public penitents. The men who repented of their sins bestrewed themselves with ashes and wore sackcloth. The penitents did not enter the church again until Maundy Thursday after having won reconciliation by the toil of forty days' penance and sacramental absolution.

Ash Wednesday Priest distributing ashes. Reuters

3) Nowadays the ashes are a way to say that we repent of our sins. In earlier times, the distribution of ashes was followed by a penitential procession, however it is not prescribed now.

4) When applying the ashes, the priest or minister says one or both of the following: “Remember that thou art dust, and to dust thou shalt return.” Genesis 3:19, and “Repent, and believe the Gospel.” Mark 1:15

5) The ashes used are typically gathered from the burning of the palms from the previous year's Palm Sunday. Sometimes they’re mixed with holy water or oil.

6) In the Catholic Church, Ash Wednesday is observed by fasting, abstinence from meat, and repentance, a day of contemplating one's transgressions. In other Christian denominations these practices are optional, with the main focus being on repentance.