Substract from Different Rows on a Table

Hi, Anonymous 

I modified data to reproduce your scenario.

Table:

You may create an index column in Power Query and then modify the measure or column as below.

Calculated column:

Result Column = 
var tab = 
ADDCOLUMNS(
    ALL('Table'),
    "Start",[Status Start Date]+[Start Time],
    "End",[Status End Date]+[End Time]
)
var totalseconds =  
DATEDIFF(
    MAXX(
        FILTER(
            tab,
            [Index]=EARLIER('Table'[Index])-1
        ),
        [End]
    ),[Status Start Date]+[Start Time],SECOND
)
var m = 
COALESCE(INT(DIVIDE(totalseconds,60)),0)
var s = COALESCE(MOD(totalseconds,60),0)
return
m&":"&s

Measure:

Result Measure = 
var tab = 
ADDCOLUMNS(
    ALL('Table'),
    "Start",[Status Start Date]+[Start Time],
    "End",[Status End Date]+[End Time]
)
var totalseconds =  
DATEDIFF(
    MAXX(
        FILTER(
            tab,
            [Index]=MAX('Table'[Index])-1
        ),
        [End]
    ),MAX([Status Start Date])+MAX([Start Time]),SECOND
)
var m = 
COALESCE(INT(DIVIDE(totalseconds,60)),0)
var s = COALESCE(MOD(totalseconds,60),0)
return
m&":"&s

Best Regards

Allan

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