Maundy Thursday is always the Easter week Thursday before Good Friday. The name orginated in England and Scotland among the Protestant Churches. Although the Scottish Book of Common Prayer uses the name "Holy Thursday". Roman Catholics, except in England, refered to Maundy Thursday as "Holy Thursday". In the Eastern Orthodox Church, tradition it goes by Great and Holy Thursday.
The word Maundy is an English derivative of the Latin mandatum, the first word of the phrase "Mandatum novum do vobis ut diligatis invicem sicut dilexi vos" (Jesus's statment "A new commandment I give unto you, That ye love one another; as I have loved you" in the John 13:34.")
On this day four events are remember: Christ's washing of the Disciples' Feet, the sharing of the Last Supper with the disiples, Christ's agony in the Garden of Gethsemane, and His betrayal by Judas Iscariot.
graphic: Salvador Dali's 1955 painting 'The Sacrament of the Last Supper"