Of course, the WT taught it was 606 BCE because in their maths they counted a zero year.
1 BCE...0 CE...1 CE.
Whilst there is no zero year.
1 BCE...1 CE
So when they realized their mistake you would think, if being honest (don't snigger) that you adjust your end date of a prophecy to 1915 because...well...you cannot change a date in history.
It would be like me say I'm 30 years old...looking at my birthday...realize I'm 31 but then adjust the year I was born to suit that I am 30.
The fact the WT is willing to adjust a date set in stone in history (forget the 587/586 bit for now) rather than the end date of a prophecy is clear that they simply want it to fit to 1914 no matter what.
There are over 13,000 tablets that show the destruction was 587/586 BCE...it is irrefutable.
The WT only stance is "well the bible is inspired...the 1914 is true therefore it must be 607 BCE".
I'll repeat...the fact they adjusted the date in history marked by events and recorded by a people who recorded everything rather than adjust the date of the end of their prophecy shows what they are...a cult.