'First Day' in the Bible

During the eleventh year, on the first day of the month of our captivity, this message came to me from the LORD:

On the first day of the first month of the twenty-seventh year of our captivity, a message came to me from the LORD, who had this to say:

On the first day of the third month of the eleventh year of our captivity, this message came to me from the LORD:

On the first day of the twelfth month of the twelfth year of our captivity, a message came to me from the LORD, who had this to say:

"This is what the Lord GOD says, "On the first day of the first month, you are to present a young bull without defect in order to cleanse the sanctuary.