537 BCE-70 years= 607 BCE
WT has always explained that Babylon fell in 539 not 537 and that the 70 years did not start until after Gedaliah was assasinated also that Jews did not leave Babylon in 539 and it took time to get there and that the land lay desolate until the first Jew set foot on eretz Israel in 537– But that is all extrapolation. We do know, however, —because it is a historical fact—that Babylon fell in 539. Although I believe that WT extrapolation is correct, it cannot be proven. The pivotal date 539 though is fact and God’s word says land desolate 70 years.—That we know.
The Reference Bible refers ( or referred if this has been changed ) to the end of the Gentile Times as circa 1914 and not 1914. 1914 is based on 537.
Simply put, 539-70 is 609. Ball park, circa, around = 607 and 1914. 537 is not a “historical date” although 539 is.