Lazarus Saturday, in the Orthodox Church and those Eastern Catholic Churches which follow the Byzantine Rite, is the day before Palm Sunday, and is liturgically linked to it. The feast celebrates the resurrection of Lazarus of Bethany, the narrative of which is found in the New Testament Gospel of John (John 11:1-45). It is the first day of Holy Week.
Lazarus Saturday and Palm Sunday together hold a unique position in the church year, as days of joy and triumph interposed between the penitence of Great Lent and the mourning of Holy Week.[1]
(... from Wikipedia on 2012-04-17 15:21:38)