Triduum
The three-day liturgical sequence from Holy Thursday evening through Easter Sunday.
The Triduum (from Latin triduum, "three days") is the three-day liturgical sequence celebrating the Paschal Mystery: Holy Thursday evening (the Mass of the Lord's Supper), Good Friday (the Celebration of the Lord's Passion), and Holy Saturday into Easter Sunday (the Easter Vigil and Easter Day). In Catholic understanding the Triduum is celebrated as a single liturgical action across the three days, with the Easter Vigil as its highest moment. Anglican and Lutheran traditions celebrate parallel rites; Mainline Protestant and evangelical practice focuses on Good Friday and Easter Sunday with less emphasis on Maundy Thursday and the Vigil.