A1:E1 = 1,2,3,4,5
A2:E2 = 1/1/17,1/8/17,1/17/17,1/23/17,2/2/17

So I have an index row, and a row of dates beneath it. I want to get a count of the number of times that there are more than 8 days in between 2 consecutive dates. I can accomplish this individually with the formula:

=if(datedif(a2,b2,"D")>8,TRUE,FALSE) and then counting the number of TRUE values.

My issue is that I want to be able to formulate this as an array instead of a bunch of individual formulas.
Below is my attempt at that. My idea was to return an array with TRUE values for each set of consecutive dates that have more than 8 days between them and FALSE values where that is not the case. And then count the number of TRUE values. It did not work.

{countif(if(datedif(a2:d2,b2:e2,"D")>8,TRUE,FALSE),TRUE)} CTRL+SHIFT+ENTER


Is there a way to formulate an array formula that accomplishes my goal?