'First Day' in the Bible

And on the first day of unleavened bread, when they sacrificed the passover, his disciples say unto him, Where wilt thou that we go and make ready that thou mayest eat the passover?

And very early on the first day of the week, they come to the tomb when the sun was risen.

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