Desperately need help with DATEDIFF calculation

Hi pbi_qwerty ,

Please, add new calculated column using this DAX:

DaysCreatedToOpening = 
VAR ThisVacancy     = 'PageUp_JobSourceData_Consolidated'[Vacancy Vacancy No.]
VAR ThisJobSource   = 'PageUp_JobSourceData_Consolidated'[Job Source Sourcing channel]
VAR MinJobSourceForVacancy =
    CALCULATE(
        MIN( 'PageUp_JobSourceData_Consolidated'[Job Source Sourcing channel] ),
        ALLEXCEPT(
            'PageUp_JobSourceData_Consolidated',
            'PageUp_JobSourceData_Consolidated'[Vacancy Vacancy No.]
        )
    )
RETURN
IF(
    ThisJobSource = MinJobSourceForVacancy,
    DATEDIFF(
        'PageUp_JobSourceData_Consolidated'[Vacancy Date created Date],
        'PageUp_JobSourceData_Consolidated'[Vacancy Source Opening Date Date],
        DAY
    ),
    BLANK()
)

Your finally output will look like this: