Perhaps a quick overview is helpful here to know what we're dealing with. Here are three primary interpretations of the 70 years.
1. Servitude of the nations to Babylon, some expresed from 609 to 539 BCE.
2. JWs focussing on the land being desolate for 70 years from the fall of Jerusalem until the 1st of Cyrus, dated from 607 to 537 BCE.
3. Josephus who inserts a 70-year period of servitude from the last deportation in year 23 of Nebuchadnezzar to the 1st of Cyrus.
Please note, however, that for #2 and #3, you must add years to the NB Period timeline. Essentially the NB timeline is 26 years too short per Josephus. That brings up the issue of revisionism.
At this point, though, it is academically required to look at a completely secularly independent Bible chronology, so that we are actually comparing the Bible's own timeline to whatever optional secular timelines are out there. The most direct Biblical reference we have for dating the NB Period is linked with the "70 weeks" prophecy which begins in 455 BCE. The first choice for the fulfillment of that prophecy clearly would be the 1st of Cyrus and when the Jews first began to rebuild. No one will argue this is the first implied reference. Even COJ in his book GT3 says that and even quotes several scriptures where the Bible claims Cyrus was supposed to rebuild Jerusalem and the temple, thus making us wonder why he didn't fulfill that prophecy? Of course, a strict Biblicalist, like Martin Anstey has no problem dating the 1st of Cyrus c. 455 BCE and presuming the Persian and Babylonian records and timeline must be in error and revised. He does this in his "Romance of Bible Chronology" published in 1913. So those thinking the 1st of Cyrus must be fulfilled in 455 BCE based upon strict Biblical dating, all the above date applications in #1 and #2 based upon the fall of Babylon in 539 BCE is not relevant.
In the meantime, since Josephus' 70-year reference is easily coordinated with the Biblical's specific reference that the 70 years were served by those last deported, a new timeline based upon strict Biblical chronology is established for year 23 of Nebuchadnezzar, which is 525 BCE. Now initially this would stand out as a date that completely is unsupported by the secular records and directly contradicts astronomical records, like the VAT4956, which dates year 37 of Nebuchadnezzar to 568 BCE. But upon reexamination of this record, two "errors" were found to dated to 511 BCE. What is of critical interest is that this dating agrees with the strict Biblical timeline that dates the last deportation in 525 BCE, year 23 of Nebuchadnezzar, which means year 37 falls in 511 BCE.
So at this point we understand what has happened. The Persians revised the NB timeline but when it came to revising the astronomical texts, they did revise some of them but decided to leave cryptic references to the original chronology in a couple of "diaries". Thus both the VAT4956 and the SK400 have double-dating in them, with relevant dates for the revised chronology and the original chronology. The only other academic challenge is removing 82 years of fake history from the Persian Period, which upon assuming the task is easily done. The Persian Period is called the "darkest period in human history" and it immediately implodes upon itself as does the 56-year expanded Greek period.
So while #1 and #2 theories on the 70 years might work out, it is only relevant for those who are using the outdated revised NB timeline. For those who have updated to the original timeline where 455 BCE is the 1st of Cyrus and the NB Period is 26 years longer than the current revised records show, the 70-year reference works just fine for 70 years of the land being desolate in direct riciprocation of the time the people "were removed off their land" at the time of the last deportation. Any 70-year theory, therefore, using the revised date of 539 BCE for the fall of Babylon (instead of 562 BCE) is thus totally spurious at this point.
In the meantime the reason for the revisions and the corrections are all outlined here:
http://www.geocities.com/siaxares/709guide.html
As I noted, the date of the Exodus and hiding the fact that Xerxes and Artaxerxes were the same king or that Aristotle and Socrates were lovers has been rather aggressively done in the literature. It is not that upon looking it wasn't apparent, it's just too problematic, especially in the past with Judeo-Christian polemics to open up this sensitive area of the ancient chronology, especially since it affected prophecies regarding the messiah.
Same thing going on now. Whereas it is a clear contradiction for secular Judaism to correct the timeline which will point to 29 CE as the correct time for the appearance of the messiah, JWs can't readily change their 607 BCE dating since it would move 1914 as the second coming to 1992; and they have no relevance to explain that. I mean, what happened in 1992 compared to WWI in 1914 as evidence of Satan being kicked out of heaven, right? So keeping the people uninformed or fooled and avoiding the revision options has been the way to go. But fortunately there is enough in place now from secular records to harmonize the Biblical timeline now, for those who need or want to follow the Bible closely, which requires that Cyrus fulfill what the Bible says he was to fulfill, which was to begin the building of Jerusalem and the temple, thus dating the 1st of Cyrus to 455 BCE to fulfill the "70 weeks" prophecy. Thus 607 BCE and 587 BCE in connection with the fall of Jerusalem are two false dates competing with each other and are irrelevant to what the Bible actually teaches.
JC
