I've always thought that there are two 70 year periods that run somewhat parallel to each other. First one from 609bc to 539bc for Babylonia and the second one from 587/6bc to 517/516bc for Jerusalem. The actual exile would then be about 50 years.
I suppose this has been discussed to death before though...
Discussed to death? Here, no way. just go to the search facility and type in 70 years
I find it interesting. When i first set out to look at 587/6 v 607 i didn't realise the subject would be so vast and deep. I am still learning. My next step is to read both Johnson's and Furuli's books.
Paul