Calculating Intervals Between Separate Rows of Data

[adventurer7]

Hi everyone! Really new to PowerBI (when I say new, I just started fiddling with it a week ago)

and I'm having a problem working on this with DAX. I found a similar thread but it doesn't deal with two columns and filtering for more than 4 hours. Feel free to point me in the right direction otherwise.

We need to calculate the total interval between the END and START (of next entry) for each person, while ignoring intervals more than 4 hours.

		START	END
1	Person 1	5/1/22 15:00	5/1/22 15:30
2	Person 1	5/1/22 20:10	5/1/22 20:30
3	Person 1	5/1/22 20:40	5/1/22 21:00
4	Person 2	5/1/22 20:40	5/1/22 21:45
5	Person 1	5/1/22 21:30	5/1/22 21:40
6	Person 2	5/1/22 21:50	5/1/22 22:00
7	Person 3	5/1/22 22:00	5/1/22 23:00
8	Person 3	5/2/22 3:00	5/2/22 5:00
9	Person 3	5/2/22 5:20	5/2/22 5:30

- In this case, the interval between END 1 and START 2 will not be added to the computation because it is more than 4 hours

The expected output will be as follows :

Person 1 : 0:40 (0:10 + 0:30)

Person 2 : 0:05

Person 3 : 4:20 (4:00 + 0:20)

Hope anyone can help me with this as I'm still struggling to combine expressions/measures. Also hope I explained the problem clearly... Thanks in advance, MVPs!

[lbendlin · Accepted solution]

Does it have to be DAX?  This can be solved quicker in Power Query.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("hdAxCsMwDAXQqxjPgVhfVtr6FNlNxq4ttPeHOKoFcYjTzV/o8YVz9uT84Ofn5/t+OX07GWkEHEkK4TDgMliG7NFDCInCYWCIL1BUZJlKs5K4I/hDoiiRbgvpJQ35tUzdFkrSENhhtx3hhqD+mmU2cj8h2FZ0YwOaxPYfvX1JqA01cgHLCg==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Person = _t, START = _t, END = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"ID", Int64.Type}, {"START", type datetime}, {"END", type datetime}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"Person"}, {{"Rows", each _, type table [Index=nullable number, Person=nullable text, START=nullable datetime, END=nullable datetime]}}),
    idx = (tbl)=>Table.AddIndexColumn(tbl, "Index", 0, 1, Int64.Type),
    #"Added Index" = Table.AddColumn(#"Grouped Rows","Rows2",each idx([Rows])),
    diff = (tbl)=> Table.AddColumn(tbl, "Difference", each if [Index]=0 then null else if [START]- tbl{[Index]-1}[END] <= #duration(0,4,0,0) then [START]- tbl{[Index]-1}[END] else null),
    #"Added Custom" = Table.AddColumn(#"Added Index","Rows3",each diff([Rows2])),
    #"Removed Other Columns" = Table.SelectColumns(#"Added Custom",{"Rows3"}),
    #"Expanded Rows3" = Table.ExpandTableColumn(#"Removed Other Columns", "Rows3", {"ID", "Person", "START", "END","Difference"}, {"ID", "Person", "START", "END", "Difference"})

in
    #"Expanded Rows3"

How to use this code: Create a new Blank Query. Click on "Advanced Editor". Replace the code in the window with the code provided here. Click "Done".