'Months' in the Bible
In the thirty and eighth year of Azariah king of Judah did Zachariah the son of Jeroboam reign over Israel in Samaria six months.
Jehoahaz was twenty and three years old when he began to reign; and he reigned three months in Jerusalem. And his mother's name was Hamutal, the daughter of Jeremiah of Libnah.
Jehoiachin was eighteen years old when he began to reign, and he reigned in Jerusalem three months. And his mother's name was Nehushta, the daughter of Elnathan of Jerusalem.
Nevertheless, seven months later, Nethaniah's son Ishmael, the grandson of Elishama from the royal family, came with ten men and attacked Gedaliah. As a result, he died along with the Jews and Chaldeans who were with him at Mizpah.