This would have more validity if, in fact, 2520 day/years had a more solid foundation. It should be remembered that to arrive at 1914 you have to start at 606 BCE - sorry, 607 BCE. I forgot that if you want to keep 1914 as THE year you have to 'move' the beginning if you later find a mistake in your calculations. In reality, the fall of Jerusalem has to have the same importance as 1914 - if one is wrong the other, also, has to be by default!
It amazes me that the WTS is the only organisation, body (whatever you may want to call them) which holds to the idea that Jerusalem fell in 607 BCE. Given that, by extrapolation, they have the 'truth' of 1914.
With that historical background and it's inaccuracy it scares me that they hang on so tenaciously to 1914 as such a pivotal date. Grrrr!