Substract previous row from current row (different columns)

Hi Anonymous ，

You can create a calculated column like this to meet your needs:

Time Between Visits (n)-cc = 
IF (
    MINX (
        FILTER ( 'Table', 'Table'[ROUTE ID] = EARLIER ( 'Table'[ROUTE ID] ) ),
        'Table'[Index]
    ) = 'Table'[Index],
    0,
    'Table'[STARTDATE]
        - MAXX (
            FILTER ( 'Table', 'Table'[Index] = EARLIER ( 'Table'[Index] ) - 1 ),
            'Table'[FINISHDATE]
        )
)

You can also create a measure as follows:

Time Between Visits (n) -ms = 
VAR lastindex =
    CALCULATE (
        MAX ( 'Table'[Index] ),
        FILTER (
            ALLSELECTED ( 'Table'[Index] ),
            'Table'[Index] < MAX ( 'Table'[Index] )
        )
    )
VAR Time_Between_Visits =
    IF (
        lastindex <> BLANK (),
        CALCULATE ( MAX ( 'Table'[STARTDATE] ) )
            - CALCULATE (
                MAX ( 'Table'[FINISHDATE] ),
                FILTER ( ALLSELECTED ( 'Table'[Index] ), 'Table'[Index] = lastindex )
            ),
        0
    )
RETURN
    Time_Between_Visits

Best Regards,

Community Support Team _ Joey
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