Easter, also called Pasch, or Resurrection Sunday, is a festival and holiday celebrating the Resurrection of Jesus Christ from the dead, described in the New Testament as having occurred three days after his crucifixion by Romans at Calvary. It is the culmination of the Passion of Christ, preceded by Lent, a forty-day period of fasting, prayer, and penance. The week before Easter is called Holy Week, and it contains the days of the Easter Triduum, including Maundy Thursday, commemorating the Last Supper and its preceding foot washing, as well as Good Friday, commemorating the crucifixion and death of Jesus. In western Christianity, Eastertide, the Easter Season, begins on Easter Sunday and lasts seven weeks, ending with the coming of the fiftieth day, Pentecost Sunday. In Orthodoxy, the season of Pascha begins on Pascha and ends with the coming of the fortieth day, the Feast of the Ascension. Easter is a moveable feast, meaning it is not fixed in relation to the civil calendar. The First Council of Nicaea established the date of Easter as the first Sunday after the Paschal Full Moon, the full moon that occurs on or soonest after 21 March.