The significance of Holy Thursday Except for the resurrection on Easter, Holy Thursday is possibly one of the most important, complex, and profound days of celebration in the Catholic Church. Holy Thursday celebrates the institution of the Eucharist as the true body and blood of Jesus Christ and the institution of the sacrament of the priesthood. Also referred to as Maundy Thursday, Holy Thursday is the day during Holy Week that commemorates the Washing of the Feet and Last Supper of Jesus Christ with the Apostles, as described in the canonical gospels.