'Eighteenth' in the Bible

In the eighteenth year of King Jeroboam, Abijah became king over Judah.

In the eighteenth year of Josiah’s reign, when he had purged the land and the [Lord’s] house, he sent Shaphan the son of Azaliah, and Maaseiah the governor of the city, and Joah the son of Joahaz the recorder (secretary), to repair the house of the Lord his God.

In the eighteenth year of Josiah’s reign this Passover was celebrated.