One difference between Eastern Christianity and Western Christianity is the calculation of the date of Easter (see
Computus). Most years, the Eastern Pascha falls after the Western Easter, and it may be as much as five weeks later; occasionally, the two dates coincide. Like Western
Lent, Great Lent itself lasts for forty days, but in contrast to the West, Sundays are included in the count.
Great Lent officially begins on
Clean Monday, seven weeks before Pascha (
Ash Wednesday is not observed in Eastern Christianity) and runs for 40 contiguous days, concluding with the Presanctified Liturgy on Friday of the Sixth Week. The next day is called
Lazarus Saturday, the day before
Palm Sunday. (Thus, in case the Easter dates coincide, Clean Monday is two days before Ash Wednesday.)
Fasting continues throughout the following week, known as Passion Week or
Holy Week, and does not end until after the
Paschal Vigil early in the morning of Pascha (Easter Sunday).