[RESOLVED] How to count unique items in a range (Excel)

[Mark@SF]

I have the following worksheet, named "Event Log".



I would like to count the Date field for a specific Species (column E) and return the count of unique Dates (column A). For example, in the above image there are 7 instances of the "Fox" species (4 on 1/3/2024 and 3 on 1/4/2024) but only 2 unique dates (1/3/2024 and 1/4/2024).

I would like to do this via a function instead of via VBA code.

I found a link (https://exceljet.net/formulas/count-...-with-criteria) that shows how to count unique numeric values with criteria, but I can't get it to work.

For example, the following should return a value of 2 since there are 2 unique dates (1/3/2024 and 1/4/2024) in the specified range that have "Fox" species...

{=SUM(--FREQUENCY(IF(('Event Log'!E17:E23= "Fox" ),'Event Log'!A17:A23),'Event Log'!A17:A23)>0)}

But the above example returns a value of 0, not 2.

Looking for any helpful ideas, examples, suggestions, etc.

Thanks.

[Mark@SF]

I figured out the problem. I was missing a pair of parenthesis. Here is the correct formula.

{=SUM(--(FREQUENCY(IF('Event Log'!E17:E23="Fox",'Event Log'!A17:A23),'Event Log'!A17:A23)>0))}