Maundy Thursday April 22 inclusive, but these dates fall on different days depending on whether the Gregorian calendar or Julian calendar is used liturgically. Eastern churches generally use the Julian calendar and celebrate this feast throughout the 21st century between April 1 and May 5 in the more commonly used Gregorian calendar. The liturgy held on the evening of Maundy Thursday initiates the Easter Triduum, the period which commemorates the passion, death, and resurrection of Jesus; this period includes Good Friday and Holy Saturday, and ends on the evening of Easter. The Mass of the Lord's Supper or service of worship is
Feast of the Ascension term "Holy Thursday" to mean Ascension Day is rare, and the term is more generally applied by most Christian denominations to Maundy Thursday in Holy Week. In Western Christianity, the earliest possible date is April 30 (as in 1818 and 2285), the latest possible date is June 3 (as in 1943 and 2038). In Roman Catholicism, the Ascension of the Lord is a Holy Day of Obligation and in the Anglican Communion, Holy Thursday is a Principal Feast. The three days before Ascension Thursday are sometimes referred to as the Rogation days, and the previous Sunday — the Sixth Sunday