'First Day' in the Bible

On the first day of the seventh month they began to offer burnt offerings to the Lord, even though the foundation of the Lord’s temple had not yet been laid.

He began the journey from Babylon on the first day of the first month and arrived in Jerusalem on the first day of the fifth month since the gracious hand of his God was on him.

The exiles did what had been proposed. Ezra the priest selected men who were family leaders, all identified by name, to represent their ancestral houses. They convened on the first day of the tenth month to investigate the matter,

and by the first day of the first month they had dealt with all the men who had married foreign women.