So you want to count the number of occurrence in column D where 1) the corresponding values in E are dates, and 2) the corresponding values in E are not dates. Correct?

The problem is not with the formula. You either have placed the formula in the wrong cell or you have other issues in that file. I can send you a sample file to show you how it works

However if you want me to check your file and diagnose the problem you will need to open a new question and assign an appropriate amount.

You cannot put the formula in the same columns that it refers to. The formula refers to F:F while the formula itself is in column F. Place the formula in another column and you will be good to go

I hope this helps

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