Holy Thursday is the first day of the Pascal Triduum.  This is the night of the Last Supper when Jesus institutes the Eucharist, the priesthood, and washes the apostles' feet, after which he says, "I give you a new commandment: love one another. As I have loved you, so you also should love one another." (John 13:34)  The tabernacle is empty, the Eucharist is put in a place of repose, and the altar is stripped. We are invited to remain in silent Adoration with the Eucharist in repose.

Holy Thursday is thus sometimes called Maundy Thursday because it was on this day that Christ gave us the new commandment--the new mandate--to love one another as he loves us. The word "Maundy" is derived from the Latin word  mandatum, or "mandate."