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
Maundy Thursday explained to the Apostles the significance of his action of washing their feet. The phrase is used as the antiphon sung in the Roman Rite during the Maundy (Ecclesiastical Latin: "Mandatum") ceremony of the washing of the feet, which may be held during Mass or as a separate event, during which a priest or bishop (representing Christ) ceremonially washes the feet of others, typically 12 persons chosen as a cross-section of the community. In 2016, it was announced that the Roman Missal had been revised to allow women to participate as part of the 12 in the Mandatum; previously, only