Breaking a Date Range into 5 Min Interval Performance Issue

Mann -

Change to Duration.TotalMinutes:

#"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each List.DateTimes([Start Time],(Duration.TotalMinutes([End Time]-[Start Time])/5),#duration(0,0,5,0))),

 
I know you still need to work on the rounding to 5 minute increments; I just did what I readily knew how to do from other projects I've worked on.

Mann  -

Meh, there's an error at Midnight that needs to be addressed. It's closer though

Here you go, try this:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUTI00De01DcyMLRUsLAyMFJw9EUXNLQACcbqRCs5QaUsIFKWVgaGGOotrQxNwepjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [#"Individual Id" = _t, #"Start Time" = _t, #"End Time" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Individual Id", type text}, {"Start Time", type datetime}, {"End Time", type datetime}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each List.DateTimes([Start Time],(Duration.TotalMinutes([End Time]-[Start Time])/5),#duration(0,0,5,0))),
    #"Expanded Custom" = Table.ExpandListColumn(#"Added Custom", "Custom"),
    #"Added Custom1" = Table.AddColumn(#"Expanded Custom", "Custom.1", each Date.From([Custom])&Time.From(Number.RoundUp(288*Number.From(Time.From([Custom]))/1)/288))
in
    #"Added Custom1"

Used the solution at https://community.powerbi.com/t5/Desktop/Round-Down-to-Nearest-30-Minute-Interval-Query-Editor/td-p/514248 for rounding and the video.

Let us know if it's faster and accomplishes your goal.

Hi ChrisMendoza 

You are right there is no issue with the number of records this code is generating. If you see the highlighted part in the screenshot you provided:

Custom.1 should be: 10/20/2019 12:00 AM not 10/19/2019 since clock would move to next day at 12:00 AM.

I added this code for Custom.1 and it fixed the issue

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUTI00De01DcyMLRUsLAyMHL0hYgZGULEDA0ggrE60UpOqFLYlAPFTKCqnVENNzQEKg+AKTeACBohlLtgKDe1QFcONMIAqtwVt9PRxECq3YhSbQZSHQsA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [#"Individual ID" = _t, #"Start Time" = _t, #"End Time" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Individual ID", type text}, {"Start Time", type datetime}, {"End Time", type datetime}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each List.DateTimes([Start Time],(Duration.TotalMinutes([End Time]-[Start Time])/5),#duration(0,0,5,0))),
    #"Expanded Custom" = Table.ExpandListColumn(#"Added Custom", "Custom"),
    #"Added Custom1" = Table.AddColumn(#"Expanded Custom", "Custom.1", each DateTime.From(Number.RoundUp(Number.From([Custom])*288,0)/288)),
    #"Changed Type1" = Table.TransformColumnTypes(#"Added Custom1",{{"Custom.1", type datetime}})
in
    #"Changed Type1"

Thanks for your help on this. Appreciated!!