Hello Nobleheart,
As Blacksheep already suggested, please draw a list of all the Neo-Babylonian Kings with the years they reigned. Your WT Lib Cd-Rom has this information available. The last king will be Nabonidus, the 1st one Nabopalassar, Nebuchadnezzar's father. count all these years together. You know the moment the Babylonian empire ended, 539 BCE. Calculate the 1st year of Nabopalassar. Please find now in your WT-Lib the moment Babylon attained its supremacy status. in the Insight book you will find under 'Assyria' that it was in the 17th year of Nabopalassar. calculate what year this was. Now take your bible and read Jer 25:12. Here you find bible prophecy confirmed that between the 17th year of Nabopalassar and 539BCE there are exactly... 70 years, as foretold in the bible. Jer 25:11 confirms that NationS (plural S) will have to serve the King of Babylon 70 years. Now you can take any bible verse that states in which year Nebuchadnezzar destroyed Jerusalem. Depending on the verse it was his 18th or 19th year (depending on the viewpoint of the writer). please calculate now in which year BCE this took place. The math really is straightforward.
The most quoted verses by the organization are 2Chron36:20, 21 and Daniel 9:1,2. Both refer directly to the verses in Jer 25, and thus can only be used together with Jer 25.
To top it up, both verses in Zecharia (1:12, 7:5) say the jews were fasting already for 70 years at that time. As Zecharia wrote his book around 515-520 BCE, and 70 years before 515-520 BCE, brings us to 590-585, it confirms what you found above.
the only real difficult one is Jer 29:10. Because Hieronymus ('Jerome' in french), used 'in' instead of 'for' in his Latin Vulgate, and this error was copied in the english King James version and all its descendants, quite a few bibles use the same word incorrectly. However, the specialist in the use of this word, a professor in Switzerland, who spent his entire oeuvre on this, stated that the Akkadian 'le' cannot be translated as 'in' in this particular verse. I am quite sure you will be able to find translations in your own languages whith the correct translation.
the simple logic above blew me and my wife away. Please do not hesitate to reply if you cannot agree with what I wrote above.
I am also living in Europe, and English is not my 1st language either. Maybe I can give you a hand with the language issue. Please check your PM.
keep your hope alive, you are getting closer to finding truth, and truth will set you free.
Best Regards,
Hoffnung