Calculating work days between two dates
I have a few questions in regards to calculating work days between two dates. I followed the instructions posted in the following link and it doesn't quite work as I would expect it to.
First, say I have the start date on a monday and end date on a friday the returned calculation is 4 but my logic says the end date is inclusive therefor it should return 5. A quick "+ 1" at the end of the calculation fixed this but I'm worried I'm missing something. I tried understanding the entire calculation but can't seem to wrap my head around this one which is why I'm worried adding a + 1 arbitrarily at the end isn't smart.
Second, the holiday exclusion assumes someone will never put a holiday as a start date but that doesn't mean a user may not mistakenly do so ... is there a way to fix this or that's the limitation of this current calculation?