Busy, busy day today so my mathematically challenged mind isn't up to, it so I am putting it out there for you-
If indeed the calendars are two months later, being dated according to the constellations, and Rosh Hashanah was actually November 8th, which is the date you had set as the 2520 day deadline;would this not affect your timeline?
Wouldn't the Day of Atonement 2017 be two months (two moons) later as well??
So, what would the revised "drop dead" date for the beginning of the Trib, according to the possible delaying of the calendar by 2 months?
I hope this makes sense!