In the thirty-first year of Asa’s reign over Judah, Omri became king of Israel, and he reigned twelve years, six of them in Tirzah.
Jewish Publication Society of America Version (JPS1917) - 1 Kings 16:23 >In the thirty and first year of Asa king of Judah began Omri to reign over Israel, and reigned twelve years; six years reigned he in Tirzah.