Easter Sunday – March 31 According to the United States Conference of Catholic Bishops, Easter is the celebration of the Lord's resurrection from the dead, culminating in his Ascension to the Father and sending of the Holy Spirit upon the Church. Easter begins the season of the church that sees celebrations of Divine Mercy Sunday, the ascension of Jesus to Heaven after his resurrection and culminating with Pentecost, when the Holy Spirit was sent to the apostles. (John 20:1-9)