Easter known as Holy Week, is very special in the Christian tradition. The Sunday before Easter is Palm Sunday, with the Wednesday before Easter being known as Spy Wednesday. The last three days before Easter are Maundy Thursday, Good Friday and Holy Saturday (sometimes referred to as Silent Saturday). Palm Sunday, Maundy Thursday and Good Friday respectively commemorate Jesus' entry in Jerusalem, the Last Supper and the Crucifixion. Maundy Thursday, Good Friday, and Holy Saturday are sometimes referred to as the Easter Triduum (Latin for "Three Days"). Many churches begin celebrating Easter late in the evening of Holy Saturday at a
Perennial calendar year after year. Advantages claimed for a perennial over an annualized calendar like the Gregorian are simplicity and regularity. Scheduling is simplified for institutions and industries with extended production cycles. School terms and breaks, for example, can fall annually on the same dates. Month-based ordinal dating ("Fourth Thursday in November", "Last Monday in May") will be obsolete. Two methods favored for perennializing the calendar are the introduction of so-called "blank days," and of a periodic "leap week." Blank-day calendars remove a day or two (the latter for leap years) from the weekday cycle, resulting in a year length of 364