DATEDIFF with blanks and nulls

[mikaelim]

Hello, 

I have to calculate the difference in number of days between two columns. The problem I am having with Date Diff is that the second column includes 'N/A's and blanks. Here's the details. It's dates a call was placed and returned. 

If the second column has the SAME DATE as the first, that means call was returned same day and the difference would be 0. If the second column has an N/A, that measn the call was answered in real time and these must be treated separately as they should not get mixed with same day return calls. If the second column has a blank, that means the call was never returned. 

How do I handle both Blanks in NAs in the formatting?

How do I modify the fx DateDiff to ignore the Blanks and NAs?

[lbendlin]

You're on the right track. First you need to define clear business rules for each scenario (N/A and <blank>  are separate scenarios!) and then you modify your DAX accordingly.  Use SWITCH() and COALESCE() - they are your friend.