Grouping Date sets within a month

Hello johnlhaase 

check out this solution. I hope I got you right. The group-function with GroupKind.Local does the trick here

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("jdOxDYMwGEThXVwj2b7f4KTNAhkAsQL7l1iCQ1TJkyy78Nc93bqmmmtWUUlTij6P+9NbG88499c2/XGCLqBr0M3QLdB16F7QvaGrhUJQ5LufFEQxBV1MQRpTUMcUBDIFjUxBJlNQ6qICrUx5LfFa4rXEa4nXEq8luijRSYluKnineHTSL6rMpbAMLJ1zOwA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Start of Month" = _t, EmpID = _t, Fleet = _t, OnOff = _t, #"Rotation Date" = _t]),
    TransformDate = Table.TransformColumns(Source,{{"Rotation Date", each Date.From(_,"en-US"), type date},{"Start of Month", each Date.From(_,"en-US"), type date}}),
    Group = Table.Group(TransformDate, {"EmpID", "OnOff"}, {{"AllRows", each _, type table [Start of Month=date, EmpID=text, Fleet=text, OnOff=text, Rotation Date=date]}}, GroupKind.Local),
    AddMin = Table.AddColumn(Group, "Min", each List.Min([AllRows][Rotation Date]), type date),
    AddMax = Table.AddColumn(AddMin, "Max", each List.Max([AllRows][Rotation Date]), type date),
    ExpandGroupedTable = Table.ExpandTableColumn(AddMax, "AllRows", {"Start of Month", "Fleet", "Rotation Date"}, {"Start of Month", "Fleet", "Rotation Date"})

in
    ExpandGroupedTable

Copy paste this code to the advanced editor in a new blank query to see how the solution works.

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Have fun

Jimmy

Hello

You are correct. I did ask about the same month. This is a large data set and when I was going through the restlts I realized some of the On/Off days transition into the following month. 

The first solution is fantasitic and is very useful. I wish I realized the data set had the transition issue priro to my first post. The law of unintended consequences. Anyways I am trying to get the scripts to ignore the start of month all together and just get the min/max for each On/Off sets.

Thanks for your time

John