Although Christians had practiced some period of preparation for the Festival of the Resurrection at Easter almost from the time of the apostles, it was not until after the Council of Nicea in 325 that forty days was established as a time of fasting and prayer. Various congregations and denominations within Christianity observe Lent with local traditions, and calculate the days differently. Like the Muslim season of Ramadan, the purpose of Lent is to deepen religious devotion through prayer, fasting and sharing of resources.
Easter is a moveable Feast. The Council of Nicea set it for the Sunday following the paschal full moon, which is the full moon that falls on or after the vernal (Spring) equinox. This is the formula used by most churches in the West, so Easter will fall on April 5, 2015. However, the Eastern Orthodox continue to use the older, Julian Calendar. This year, Easter will be celebrated on Sunday, April 12, 2015 by Eastern Orthodox churches.
The first day of Lent is Ash Wednesday, a day of fasting and repentence on which Christians are traditionally anointed with ashes and reminded “Remember, that dust thou art, and unto dust shalt thou return. “ From Ash Wednesday to Holy Week, the forty days are calculated to exclude Sundays, which are feast days.
At the end of Lent, Holy Week begins on Palm Sunday, with the commemoration of Jesus’ ride into Jerusalem. In many churches, the story of Jesus’ death on the cross is also read on this Sunday. There are worship traditions attached to each day of Holy Week, especially Maundy (or Holy) Thursday and Good Friday, which is the end of Lent.