They are not really dividing 2520 by 365 to find out where the 2520 years end.
I don't know very much about this subject, but the way I understand it is:
Basically, they are saying x = 2520 / 7 = 360, where x = the days in a year.
Then they are taking 2520 and subtracting 607 to get 1913. Adjusting for the turn from 1 BCE to 1 CE, they add one year to get 1914.
However, they fail to recognize that the date 1914 is from the Gregorian calendar, which would mean x = 365.24
So even if you were to assume the pivotal date 607 BCE is correct to begin with, the actual numbers you would have to use to arrive at 1914 would be incorrect as well.
Did I get this right?