I have two Date columns and the difference of these two columns in Excel (all negative numbers).
Then I created a Column using simple DAX formula to substract these columns just like in Excel and then changed the format of the column to Whole Number. I got same result so it is OK up till now.
Now, when I create a measure to calculate the average of these values, I get two different result, a negative result when I use the column calculated in Excel (correct result) and a positive result when I use the column created with DAX!!! Apparently there is a problem with the column format and I don't know how to fix it.