Alleymom's (Marjorie's) K.I.S.S. approach:
Ok, here's my "Keep It Simple, Sweetie" approach to 586/587 BCE. All you have to do is be able to count backwards.
The names and regnal lengths of the Neo-Babylonian kings are known. If you start at 539 BCE for the fall of Babylon, a date which is accepted by the WTS and secular historians, and list the years of the kings in reverse order, it is very easy to see that Jerusalem was destroyed in 586/587 BCE.
There are only 5 Babylonian kings to deal with. It isn't hard. You don't need to bother with VAT 4956, Josephus, Ptolemy, Anstey, Bullinger, etc. etc. Just go by the actual kings, whose names and regnal lengths are known from tens of thousands of cuneiform tablets from many different towns and villages all over southern Mesopotamia. It is so simple a child could do it.
Note: Perhaps you are thinking, "But does the WTS agree with the list of the kings and the lengths of their reigns?" The surprising answer is YES! I recently bought a Watchtower Library 2001 CD and found quotations from WTS articles and books which show that the WTS itself has agreed with secular historians regarding the names and lengths of reign of the 5 kings listed below.
(There are also articles which try to dance around this, but the fact remains that in their own literature at various times they have agreed with the length of each king's reign. I will provide the quotations in my next post.)
Just start with Nabonidus, the last Babylonian king, and work backward.
Babylon falls to Cyrus the Persia -- 539 BCE
Nabonidus -- 17 years
Labashi-Marduk -- 3 months (WT says less than 9 months)
Neriglissar -- 4 years
Evil-Merodach -- 2 years
Nebuchadnezzar -- 43 years
Nabonidus -- 17 years
Year 17 = 539 BCE
16 = 540
15 = 541
14 = 542
13 = 543
12 = 544
11 = 545
10 = 546
9 = 547
8 = 548
7 = 549
6 = 550
5 = 551
4 = 552
3 = 553
2 = 554
1 = 555
0 = accession year = 556
Labashi-Marduk -- less than a year
3 months in 556
Neriglissar -- 4 years
4 = 556
3 = 557
2 = 558
1 = 559
0 = accession year = 560
Evil-Merodach -- 2 years
2 = 560
1 = 561
0 = accession year = 562
Nebuchadnezzar -- 43 years
43 = 562 BCE
42 = 563
41 = 564
40 = 565
39 = 566
38 = 567
37 = 568
36 = 569
35 = 570
34 = 571
33 = 572
32 = 573
31 = 574
30 = 575
29 = 576
28 = 577
27 = 578
26 = 579
25 = 580
24 = 581
23 = 582
22 = 583
21 = 584
20 = 585
19 = 586 BCE
18 = 587 BCE
So Jerusalem was destroyed in 586/587 BCE by Nebuchadnezzar. See the next post for quotations from WT literature which support the regnal lengths for each king listed above.
Marjorie