'First Day' in the Bible

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

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

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