'First Day' in the Bible

And on the first day of unleavened bread, when they killed the passover, his disciples said to him: Where dost thou wish that we go and prepare that thou mayest eat the passover?

And very early, on the first day of the week, when the sun had risen, they came to the sepulcher.

Now when Jesus had risen early on the first day of the week, he appeared first to Mary Magdalene, out of whom he had cast seven demons.