 The calendars for reckoning the years of kings in Judah and Israel were offset by six months, that of Judah starting in Tishri (in the fall) and that of Israel in Nisan (in the spring).Cross-synchronizations between the two kingdoms therefore often allow narrowing of the beginning and/or ending dates of a king to within a six-month range.A study of the relevant texts in Scripture allows the narrowing of the start of the Pekah/Menahem rivalry on the death of Shallum to the month of Nisan, 752 BC, as Thiele showed in the second edition of "Mysterious Numbers", pp.