Easter is the celebration of Christ’s resurrection from the dead. It is celebrated on Sunday, and marks the end of Holy Week, the end of Lent, the last day of the Easter Triduum (Holy Thursday, Good Friday and Easter Sunday), and is the beginning of the Easter season of the liturgical year.
Matthew 28:6-7
He is not here, for he has risen, as he said he would. Come and see the place where he lay, then go quickly and tell his disciples, “He has risen from the dead, and now he is going ahead of you to Galilee; that is where you will see him.” Look! I have told you.’