'First Day' in the Bible

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

And the sons of the captivity did so. And Ezra the priest, [with] certain heads of fathers, after their fathers' houses, and all of them by their names, were set apart. And they sat down in the first day of the tenth month to exami

And they made an end with all the men who had married foreign women by the first day of the first month.