The Great Vigil, when observed, is the first liturgy of Easter Day. It is celebrated at a convenient time between sunset on Holy Saturday and sunrise on Easter morning. It is appropriate that the service begin in darkness. The liturgy normally consists of four parts:

The Service of Light: a new fire is kindled, and from it the Paschal Candle is lit, symbolizing Christ, the light of the world. The Exsultet, an ancient song of praise, is sung or said as the climax of this part of the liturgy.