To count the number of days in a range is very simple.
Eg: I want to count the number of days between 1/1/9 and 22/4/9
If cell A1 is start date (1/1/9), and cell B1 is end date (22/4/9), and the result will appear in cell C1, then the formula in C1 is simply = B1-A1
But, the trick is, you have to format cell C1 to be a General Number with no decimals, otherwise is just returns another date format response. Result in this example is 111 days.
Hope this helps.