The webpage below has some new details.
My original thought in the book was 7 months to cleanse the Land would work from Purim to Tabernacles.
However, could not the 7 months to bury the dead span from two months later to arrive at the Dedication--Hanukkah?
From May 5th to Dec 5th (Hanukkah) is 214 days.
 
More coming . . .
 
http://jesus2006.org/signsoftheend/Moses120.html