Hi Lyle,
 
Every seven Hebrew years contains 85 moons (ie 85 months), not 84. That is why once every seven Hebrew years there is both the month of Adar I and the month of Adar II in one year. Yes, there are 42 months (1,260 days) in the first-half of the 70th Week of Daniel, but there are 43 months (1,290 days)  in the last-half of the 70th Week. Here is the proof:
 
Daniel 12:11
"From the time that the daily sacrifice is abolished and the abomination that causes desolation is set up, THERE WILL BE 1,290 DAYS."
 
Merry Christmas
 
YBIC, Bruce Warner