Scholar,
Pennycandy mentioned LBAT 1420, so I'll explain to you how we can date the regnal years of Nebuchadnezzar using just one eclipse record of the dozens recorded in it.
Cuneiform tablet BM 38462 (=LBAT 1420) reports lunar eclipses for almost every year from the first year of Nebuchadnezzar II (604/603 BC) to his 29th year (576/575 BC).
The following information on lines 16-18 of the first side of the tablet gives eclipse data for year 17 of Nebuchadnezzar: Lunar Eclipse, Obv. II, 16-18: BC 587 Jan 08 (mag. = 1.80) [Obv. II, 16?-18?; trans Huber p15] [Nebuchadnezzar II, year] 17, month IV (eclipse) passed. [Month X] 13, morning watch(?) 1 beru 5 U[S] (= 35 deg) [before sunrise?] it set totally [eclipsed].
Notes: Although the interval to which the measurement of 35 deg refers is broken away, it can confidently be restored as ?before sunrise?. The characteristic style of BM 38462 is to cite the time interval measured after sunset or before sunrise near the start of a record. Since the moon set eclipsed, it is clear that the 35 deg cannot have been measured after sunset. It was a total eclipse.
The eclipse referenced earlier in the record as occurring in month IV, Duzu, would have been the lunar eclipse of July 15, 588BC.
To see if any other year matches this record we need to find an eclipse in month IV, Duzu, followed by a total lunar eclipse in month IX or X, which sets totally eclipsed. (Lunar eclipses follow 5 or 6 months after a previous one)
There are, in fact, no total lunar eclipses that set eclipsed in months IX or X in the years 625 BC to 500 BC. There are two in month XI, Shabatu, that set eclipsed, February 19, 580BC and February 10, 533BC, both of which follow an eclipse in month V. These obviously do not match the record.
The only match to BM 38462 Obv II, 16-18 is the total lunar eclipse of 08 January 587BC.
Therefore 13 Tebetu, year 17 Nebuchadnezzar = 07/08 January 587 BC.
Nebuchadnezzar year 17 = 588 BC ? 587 BC, and so his 7th year would be 598 BC - 597 BC.
Now if there is uncertainty about the exact year of the destruction of the temple, there is absolute certainty about the first capture of Jerusalem. According to the Babylonian Chronicles it was in his seventh year that Nebuchadrezzar called out his army, marched to Khatti and besieged the city of Judah. ?On the second day of Adar he captured the city and seized its king.? He then appointed Mattaniah (Zedekiah) as regent instead of the captured Jehoiachin.The 2nd of Adar (Addaru) in Nebuchadnezzar's seventh year was 16th March 597 BC.
There are also more than a dozen other observations and even more predictions on this tablet that can only refer to one specific year. This is the kind of secular evidence used to date the first capture of Jerusalem as 16th March 597 BC and the destruction as 586/587 BC.
CF.