'First Day' in the Bible

From the first day of the seventh month they began to offer burnt-offerings to the LORD. But the foundation of the temple of the LORD was not yet laid.

For upon the first day of the first month he began to go from Babylon, and on the first day of the fifth month he came to Jerusalem, according to the good hand of his God upon him.

And the children of the captivity did so. And Ezra the priest, with certain chief of the fathers, after the house of their fathers, and all of them by their names, were separated, and sat down in the first day of the tenth month to examine the matter.

And they made an end with all the men that had taken foreign wives by the first day of the first month.