Actually, all this preempted by the seventy years of "servitude" that had to be served at Babylon by those who "escaped from the sword" which is a reference to those who were in Egypt and who were deported in year 23 of Neb-II. This is quite clear from Josephus who notes those who served 70 years were those who came from Egypt.
So having noted that, we understand Zechariah 1 and 7 where 70 years after the destruction of Jerusalem expires in the 2nd year of Darius the Mede. But the Jews are still in exile. Zechariah 7 shows that 70 years of mourning in the seventh month over Gedeliah ended in year 4 of Darius the Mede. That means that Gedaliah was killed in the 20th of Neb-II and began to be mourned the following year. Thus there is a 2-year gap between the expiration of 70 years after the fall of Jerusalem and 70 years of mourning and fasting for Gedaliah. Even so, the context shows that the Jews were stillat Babylon.
But that makes perfect sense if those last deported in year 23 had to serve that full 70 years. That is, those 70 years would not have expired until 4 years after the fall of Jerusalem. So the Jews indeed were still in exile down into the 6th year of Darius the Mede, who ruled for six years before Cyrus took over the entire empire and the rule at Babylon. Thus in the 1st of cyrus is when the 70 years ended.
So the true focus in this passage of scripture should be ".... until the kingdom of Persia came to power.." This is a very, very, very specific reference. You see, the Bible makes it quite clear to distinguish the royalty of the Medes from the Royalty of the Persians. That is the primary reason for calling Darius, Dariud the MEDE and Cyrus, Cyrus the PERSIAN. Why is that? Because when the Medo-Persian Empire took over, the Medes were over Babylon. Only Darius the Mede was also the grandson of Nebuchadnezzar III and thus an official Babylonian king. He was not a Persian. After six years of rule, he abdicated to Cyrus who became king over the entire Persian Empire. At this point the "royalty of Persia" began to reign and ended the 70 years of exile of those last deported.
So you can play word games all you want to and claim the text doesn't mean precisely what it clearly says, which is the desolation and the "rest" are the same thing and both lasted 70 years. But for those who don't want to quibble with that, confront them with the seventy years of servitude of "those who escaped from the sword" who were still in exile in the 2nd and 4th years of Darius the Mede? It is thus Zechariah 1 and 7 which confirms that in actuality, Jerusalem lay desolate for 74 years after the fall of Jerusalem.
But, of course, the true big elephant in the room is that the Bible's NB Period is 26 years longer than that of current secular history, so those not addressing a direct contradiction for the Bible vs. secular history are not going to ever resolve any of this.
Now you can use Josephus at Ant. 11.1.1 which clearly shows those last deported served 70 years which ended in the first of Cyrus. Or you can use the VAT4956 which includes 2 references to the original year 37 of Neb-II in 511 BCE to correctly date year 37 to 511 BCE, year 23 to 525 BCE and 70 years following that to 455 BCE for the 1st of Cyrus. If you don't update to the current corrected references and think that 587 BCE is the date for the fall of Jerusalem, then you are simply reflecting on outdated information. The 1st of Cyrus falls in 455 BCE, the last deportation in year 23 of Neb-II falls in 525 BCE and the true fall of Jerusalem, per both the Bible and the VAT4956 date that event to 529 BCE. Until you acknowledge this, you are not discussing the true Biblical timeline, but a pagan timeline which was clearly revised during the Persian Period to expand the rule of some Persian kings.
Anyway, Zechariah 1 and 7 proves the Jews were still in exile some 70 and 72 years after the fall of Jersualem. Combined with 2 Chronicles 36 it proves Darius the Mede rule for 6 years before Cyrus came to the throne. If your chronology does not reflect this, then it is false and not Biblical. I can claim it is "false" because the VAT4956 forces us to date the 37th of Neb-II to 511 BCE whether we want to or not. Not doing so is simple incompetence at this juncture.
Bottom line is that the Bible is true, and as Josephus reflects, the 70 years of desolation of the land began with the last deportation and ended in the 1st of Cyrus and includes a 6-year rule by Darius the Mede, who was the grandson of Nebuchadnezzar II. Start there. Anything short of this has nothing to do with the Bible, so don't even mention 2nd Chronicles.
Get it right. Or get out of sight.
LS