Calculate A Customer's Second Order

HI TheGreatestGoat

You can try this MEASURE pattern

Days between second order and third order =
VAR temp =
    ADDCOLUMNS (
        VALUES ( 'Sales Fact Table'[purchase_Date] ),
        "RANK", RANKX (
            VALUES ( 'Sales Fact Table'[purchase_Date] ),
            [purchase_Date],
            ,
            DESC,
            DENSE
        )
    )
RETURN
    DATEDIFF (
        MINX ( FILTER ( temp, [RANK] = 3 ), [purchase_Date] ),
        MINX ( FILTER ( temp, [RANK] = 2 ), [purchase_Date] ),
        DAY
    )

TheGreatestGoat

Try this MEASURE to do the average

Measure =
AVERAGEX (
    ALLSELECTED ( 'Sales Fact Table'[Customer] ),
    [Days between second order and third order]
)