Date Calculator

Hi mwen90,

the DAX function DATEDIFF definition can be found here: https://docs.microsoft.com/en-us/dax/datediff-function-dax It says, the first param is StartDate and the second is EndDate. I think you should change the order in your Days expression.

Days = DATEDIFF(PlantEuipment_PlantEquipment[LastServiceDate];Today();DAY)

Then change the data type of LastServiceDay to date/time:

And I've also extend your DaysGroup logic to:

DaysGroup =
IF (
    PlantEuipment_PlantEquipment[Days] < 0;
    BLANK ();
    IF (
        PlantEuipment_PlantEquipment[Days] <= 80;
        "Within service date";
        IF (
            PlantEuipment_PlantEquipment[Days] <= 90;
            "Approaching service date";
            IF ( PlantEuipment_PlantEquipment[Days] > 90; "Service Required" )
        )
    )
)

The result: