So when He says:
Mat 24:22 And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened.
I believe him.
Ron Reese increases the number of days in the 2nd half to 1335 days.
Jesus decreases the number of days in the 2nd half.
Believe which ever one you want.
You are on the right track: we MUST believe what is written. Indeed, Jesus DID say something would be shortened, but what EXACTLY did Jesus say gets shortened? Did He specify the last half of the week, or did He specify that the 1260 days or 42 months would be shortened? No, look closely at what is shortened:
"Those days" are what get's shortened. He said, "then shall be great tribulation...And except those days should be shortened." So what is shortened? God will shorten "those days" of "great tribulation."
Therefore, it is NOT the second half of the week that gets shortened. As we say here, it is written in stone, (or concrete) that the last half of the week will be 42 months, 1260 days, 1260 days, time times and half of time, and 42 months. (Not to mention the two times Daniel tells us the last half of the week will be 3 1/2 years.)
So with these many scriptures telling us the last half of the week is written in heaven as exactly 1260 days, it cannot be this time that is shortened. You see, there will be "those days" of "great tribulation" that will begin at the abomination and go to some INDEFINITE period of time during the last 1260 days. The city will certainly be trampled for the entire 42 months, the two witnesses will surely testify for their entire 1260 days, and the woman fleeing will have her entire 1260 days. Yes, the Beast will get his entire 42 months too.
But DURING this time, God will pour out the vials of his wrath that will SHORTEN "those days" of great tribulation. These vials will make it physically impossible for the Beast and His armies to continue to hunt people down and put them to death. There will be TOO MUCH PAIN, darkness, lack of anything to drink, etc.
So the events that cause great tribulation; that is, hunting people down, and separating them from their head, will be STOPPED sometime before the last 1260 days are up. God does not tell us how far into the last half of the week it will be. In fact, I don't think we can even tell how long God will wait after the abomination before He begins pouring out the vials of His wrath.
We can be SURE then, that the entire week will last for 2520 days, and each half will last exactly 1260 days. Any numbers other than these, such as 1290 or 1335 do not change the length of the week in any way. They are speaking of events that will happen AFTER the week has concluded.
Good post, Kieth!