Calculate time difference (in minutes) between rows in the same column

[Anonymous]

Hi Everyone, 

Hope someone can assist a novice PowerBI user. 

The problem: I need to calculate the time (in minutes) between each row in the "Event Date" column (see screenshot below). 

So, for instance, I want to know the time difference between the second row and first row of the "Event Date" column. This should be 0, but if you have a look at my "Time Difference" column, something funny is going on. 

Here is my DAX code: 

Time Difference =

VAR _a =

MAX ( EventData[Event Date])

VAR _previousdate =

CALCULATE (

MAX ( EventData[Event Date] ),

FILTER (

ALLEXCEPT('EventData',EventData[Event])

,

EventData[Event Date] < _a

)

)

RETURN

DATEDIFF (

_previousdate,

_a,

MINUTE

)

Hopefully someone can help! 

Thank you. 

[amitchandak · Accepted solution]

@Anonymous , create a new column

datediff([Event Date],maxx(filter(Table, [Index] = earlier([Index])-1),[Event Date]), minute)