'First Day' in the Bible

On the first day of the unleavened bread, the disciples came to Jesus, saying to Him; Where do you wish that we may prepare for you to eat the passover?

And on the first day of the unleavened bread, when they were accustomed to slay the passover, His disciples say to Him; Where do you wish, that we, having gone away may prepare that you may eat the passover?

Then it being evening, on that day, on the first day of the week, and the doors being shut where the disciples were assembled, on account of the fear of the Jews, Jesus came and stood in their midst, and says to them, Peace be unto you.

And when they came to him, he said to them, You know, that from the first day from which I came unto Asia, how I was with you all the time,

On the first day of the week let each one of you lay by with himself treasuring up, that as to whatsoever he may be prospered, in order that there may be no collections at that time when I may come.