Count Unique Values if Adjacent Cell is Not Blank

Thanks, Tony! That seems to work.

Glenn,

The expected results for the example sheet are as follows:

If all cells in column C have values, the days worked should be 5. Each date should only be counted once, so if there are no values in C2 or C3, the result should be 4. Make sense? I was trying to use the formula in cell E6, but I couldn't figure out how to make it stop returning 0.5 for days in there twice, etc.

Thanks, all!