Easter Vigil Masses
The Missale Romanum reminds us that the Easter Vigil is the "mother of all vigils," the "greatest and most noble of all solemnities." On this night, the Church keeps watch, celebrating the resurrection of Christ in the sacraments and awaiting his return in glory. It is the turning point of the Triduum, the Passover of the new covenant, which marks Christ's passage from death to life.
The Vigil, by its very nature is to take place in the dark. It is not begun before nightfall.