Find duration spent between 2 dates in multiple rows

Hi,

I am not sure if I understodd your question correctly, but I tried to create a sample pbix file like below.

It is for creating a new column, and the result is described in Second.

Please check the below picture and the attached pbix file.

OFFSET function (DAX) - DAX | Microsoft Learn

COALESCE function (DAX) - DAX | Microsoft Learn

expected reuslt CC = 
VAR _currentdatetime = Data[Created]
VAR _nextdatetime =
    MAXX (
        OFFSET (
            1,
            SUMMARIZE ( Data, Data[Ticket num], Data[Created] ),
            ORDERBY ( Data[Created], ASC ),
            ,
            PARTITIONBY ( Data[Ticket num] )
        ),
        Data[Created]
    )
RETURN
    COALESCE ( DATEDIFF ( _currentdatetime, _nextdatetime, SECOND ), 0 )