Calculating DateDiff from different rows

Hi KingsleyZ,

Try below solution.

1. Add New Measure

MinTimeStamp = CALCULATE(min('sorted-cowrie'[timestamp]),ALLEXCEPT('sorted-cowrie','sorted-cowrie'[source_ip]))

2. Add one more measure.

MaxTimeStamp = CALCULATE(MAX('sorted-cowrie'[timestamp]),
    ALLEXCEPT('sorted-cowrie','sorted-cowrie'[source_ip]))

3. Add New Calculated Column

Duration = DATEDIFF([MinTimeStamp],[MaxTimeStamp],SECOND)

4. Add Final duration column. This will show duration in "Days HH:MM:SS" format.

NewDuration = 
VAR TotalDuration='sorted-cowrie'[Duration]
VAR Dy =TRUNC(TotalDuration/3600/24)
VAR Hrs = TRUNC((TotalDuration-Dy*3600*24)/3600)
VAR Mns =TRUNC(MOD(TotalDuration,3600)/60)
VAR Scs = MOD(TotalDuration,60)
return IF(Dy=0,"",IF(Dy>1,Dy&" Days ",Dy&" Day "))&IF(Hrs<10,"0"&Hrs,Hrs)&":"&IF(Mns<10,"0"&Mns,Mns)&":"&IF(Scs<10,"0"&Scs,Scs)

Below is the sample screenshot.

https://www.dropbox.com/s/0udpc0urba4xebr/sorted-cowrie%202018-03-15_10-19-14.jpg?dl=0

Please let me know if this helps.

Thanks,

Rahul