How to count occurrences of a comparison within an array

I have two columns of dates that look something like this:

(Column A	(Column B)
Order Received	Order Processed
02/14/2014	02/14/2014
02/15/2014	02/25/2014
n/a
02/16/2014	canceled
02/16/2014	02/17/2014
n/a	n/a
02/17/2014	02/28/2014

I'm looking for a formula that will tell me how many times the date in the first column is 5 days or less than the date in the second column. In other words, count how many times column B minus column A is less than or equal to five for the array (i.e. B-A<=5).

I have tried several formulas without success, usually because the cells with text in them throw the formula(s) off.

Here are some examples of formulas that didn't work:

=SUMPRODUCT(--ISNUMBER('2014'!$E$2:$E$1001),--ISNUMBER('2014'!$F$2:$F$1001),--('2014'!$F$2:$F$1001-'2014'!$E$2:$E$1001<=5))

{=COUNTIF('2014'!$F$2:$F$1001,('2014'!$F$2:$F1001)-('2014'!$E$2:$E$1001)<=5)}

=SUMPRODUCT(--(N('2014'!$F$2:$F$1001)-N('2014'!$E$2:$E$1001)<=5))

{=IF(ISNUMBER('2014'!$F:$F),IF(ISNUMBER('2014'!$E:$E),SUMPRODUCT(--('2014'!$F:$F-'2014'!$E:$E<=5))))}