Power BI average between different dates

Hi, bombom 

For your needs, you'll need to convert the difference to "seconds", take the average and convert the result back to time format.

Please try measure formula like:

EndAt = 
IF (
    MAX ( Logging[Step] ) = 2,
    CALCULATE (
        MIN ( Logging[CreatedAt] ),
        FILTER ( ALL ( Logging ), Logging[CreatedAt] > MAX ( Logging[CreatedAt] ) )
    ),
    BLANK ()
)

diff(second) = DATEDIFF(MAX(Logging[CreatedAt]),[EndAt],SECOND)

Average = AVERAGEX(Logging,[diff(second)])

Result1 = 
IF (
    [Average] = BLANK (),
    BLANK (),
    TIME ( 0, 0, FLOOR ( 'Souktion1'[Average], 1 ) )
)

If the total result is 30.12.1899 0:09:22, you just need to change the format of your measure.

Result:

Reference:

TIME 

FLOOR 

Best Regards,
Community Support Team _ Eason