There are 2 dates written as, for example, in one cell, say 12/2/2010 3:30 PM and another cell, say 12/7/2010 10:20 PM. The calculation that is needed is the following:

1) Total hours excluding weekends if the start and end times are not BOTH on the weekend. Also, just to be clear, a weekend is from midnight Sat to midnight Mon.

2) If either date, or both dates, falls on a weekend, then the weekend should be included.

3) The dates can span over weeks. I'm not sure what to do if the start and end dates are on the weekends here. It doesn't matter much for spans > 9 days if the weekends count or not. Your choice.

4) The output should be in a 'number' format that can be graphed; so, a 48 hour span should be graphed as the number 48.

5) The calculation can be accurate to within 3 hours; if that helps.

If this cannot be 'easily' handled, what is your closest approximation to the above?

If desired, I can give examples of all of the above scenarios in an excel spreadsheet.

Many thanks in advance!!!!!