Charles, in response to your calculations, I have been asking people this question for white a while if these rare eclipses put a parentheses around the tribulation.   I am excited that you ran with this to verify if this was something that we should be looking at based upon biblical calculations and not just another timeline to get our hopes up and crushed again.  

http://www.fivedoves.com/letters/may2011/charlesh517.htm   your post

My questioning if these rare central eclipses are the parentheses of the tribulation and if the 7 day warning or the rapture could occur by Pentecost and was JR Church right? 

My posts:
http://www.fivedoves.com/letters/apr2011/nicole47-2.htm

http://www.fivedoves.com/letters/may2011/nicole513-1.htm