DATEDIF - DATEDIF Calculation returning a negative for days or months

[DaveBre]

Hi all,

I'm looking for some help with subtracting a range of dates, from another range of dates using datedif formula.

The issue is that the end result is producing a negative number of days (-9 in this example) or months in cell E11.

Is there any way to accurately subtract a larger number of dates from a smaller, thereby reducing the months by one?

The example has an employees period of employment being reduced by a range which doesn't count as service.

Any help would be appreciated.

Thanks

David