'First Day' in the Bible

And it came to pass in the fortieth year, in the eleventh month, on the first day of the month, that Moses spake unto the children of Israel, according unto all that Jehovah had given him in commandment unto them;

You have been rebelling against him from the very first day I knew you!

And I stood in the mount according to the first days, forty days and forty nights; and Jehovah will hear to me also in this time; Jehovah was not willing to destroy thee.

And there shall be no leavened bread seen with thee in all thy coast seven days; neither shall there any thing of the flesh, which thou sacrificedst the first day at even, remain all night until the morning.

Let seven weeks be numbered from the first day when the grain is cut.