Hi,
no need complex calculation
Just look units
-607 is solar year of 365.25 days
2520 was given in prophetic year of 360 days
https://wol.jw.org/en/wol/d/r1/lp-e/1984241?q=2520++360&p=doc
A Day for a Year
How do we know that the “seven times” are 2,520 years? The calculations are made in a way similar to those made by the Watch Tower Society’s first president, C. T. Russell, in 1877 and recorded in the book he coauthored entitled The Three Worlds. This is how it is done: In Revelation chapter 12, verses 6 and 14, we learn that 1,260 days are equal to “a time [that is, 1 time] and times [that is, 2 times] and half a time,” or a total of 3 1⁄2 times. So “a time” would be equal to 360 days. “Seven times” would be 360 multiplied by 7, or 2,520 days. Now if we count a day for a year, according to a Bible rule, the “seven times” equal 2,520 years. (Numbers 14:34; Ezekiel 4:6) Therefore, the duration of the “seven times,” the Gentile Times, is from 607 B.C.E. to 1914 C.E.
You rise an error if you add nautic miles and miles ... the same here
when JW calculates 1914 in solar year they make an error of units
they don't convert prophetic year or solar year ...
-607 solar year + 2520 prophetic year != 1914 solar year
as
2 nautic mile + 2 miles != 4 miles
Best Regards
