2 Kings 14:1

second year of Joash. According to 2 Kings 13:10, Joash (king of Israel) began to reign in the thirty-seventh year of Joash (king of Judah). If Arnaziah began in the second year of Joash (king of Israel), he would have reigned only thirty-nine years. But he reigned forty (2 Kings 12:1). All depends on mode of reckoning from Nisan, and counting parts of years for complete years. This would at once explain the difference. See App-50. Our difficulty, as usual, arises from our ignorance.