Palm Sunday is a moveable feast in the church calendar observed by Catholic, Orthodox, and some Protestant Christians. It is the Sunday before Easter Sunday, and a celebration of the entry of Jesus into Jerusalem in the days before his execution. The crowd greeted him by waving palm fronds, giving the day its name. In the Roman Catholic church, it is now often referred to as Passion Sunday, and is the beginning of "Passion Week". (formerly often called "Holy Week"). In the Passion Week liturgy on Palm Sunday palm fronds are blessed outside the church building and a procession enters, singing, re-enacting the entry into Jerusalem.