'First Day' in the Bible

Upon the first day of the seventh month began they to offer burnt sacrifices unto the LORD. But the foundation of the temple of the LORD was not yet laid.

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

And the children of the captivity did even so. And Ezra the priest, and the ancient heads through the house of their fathers, and all that were now rehearsed by name, separated themselves; and sat them down on the first day of the tenth month to examine this matter.

And on the first day of the first month they made an end of all the men that had taken strange wives.