Wow, Leo. I never thought of the fact that the Society assumes extra days for the 1260 days, treating it as the equivalent to 3.5 solar years, and not taking it as a literal 1260 days.
To prove this point, the "Revelation Climax" book (pages 10-13) declares that the 1260 days, or the "time, times and half a time" of Daniel 12:7 spans from the starting point of "December 1914" up until June 21, 1918, when Rutherford & Co were thrown in prison and the "organized preaching work was killed".
But here's the rub. December 21, 1914 is exactly three and a half solar years before June 21, 1914. But if you count 1260 literal days backward from June 21, 1918 your starting point is January 8, 1915--missing the month of December, 1914 entirely!
See what I mean at: http://www.onlineconversion.com/days_between.htm
Here is proof that here the WTS makes a "time, times, and half a time" not a literal 1260 days, but inclusive of EXTRA days. If they stuck to this same methodology to determine the timespan of Daniel 4's "seven times", then they would say it represents seven solar years, admitting that 2520 days are simply representative of that time span, which is about 2557 actual days when the "extra days" are included, Essene/Sadducee calendar notwithstanding.