'First Day' in the Bible

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

And very early in the morning, the first day of the week, they came to the sepulcher at the rising of the sun:

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