Rotate column

Lefuneste57 You need to use Power Query for this:

Create a new query and paste this code in the advanced editor:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("bY+9DoMwDIRfBTFX8k8SIGO7dO+KGFBAVSQaKghD375xIUzd7rNPd3bblldiU5WX8rb5wYdn4Xz8JCQgYGSVpAHCrJOic8EEaAR0AoX/obukDja6TuPH3A+Fm8Mal81FPwdJbABZrCRAoLPmnEFH7+liUCJZ5vY4jvci2/yeuU/9uhbL+J56N77GENOshioZqZEAc3whaRYkmKykGUCVgStAfW40oN2h674=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Project = _t, #"Project Name" = _t, #"Start Date Call For Tender" = _t, #"End Date Call For Tender" = _t, #"Start Date Works" = _t, #"End Date Works" = _t, #"Start Date Finishing" = _t, #"End Date Finishing" = _t]),
    ChangedType = Table.TransformColumnTypes(Source,{{"Project", type text}, {"Project Name", type text}, {"Start Date Call For Tender", type text}, {"End Date Call For Tender", type text}, {"Start Date Works", type text}, {"End Date Works", type text}, {"Start Date Finishing", type text}, {"End Date Finishing", type text}}),
    ConvertToDate = Table.TransformColumnTypes(ChangedType, {{"End Date Call For Tender", type date}, {"Start Date Call For Tender", type date}, {"Start Date Works", type date}, {"End Date Works", type date}, {"Start Date Finishing", type date}, {"End Date Finishing", type date}}, "en-GB"),
    Unipvot = Table.UnpivotOtherColumns ( ConvertToDate, { "Project", "Project Name" }, "Name", "Date" ),
    Group = Table.Group (
        Unipvot,
        { "Project", "Project Name" },
        {
            {
                "Count",
                each 
                let
                    CurrentGroup = _,
                    GetStartDate = 
                        Table.AddColumn (
                                CurrentGroup,
                                "Start Date",
                                each
                                    if Text.StartsWith ( [Name], "Start Date" ) = true then [Date]
                                    else null
                            ),
                    GetEndDate = 
                        Table.AddColumn (
                            GetStartDate,
                            "End Date",
                            each
                                if Text.StartsWith ( [Name], "End Date" ) = true then [Date]
                                else null
                        ),
                    FillDown = 
                        Table.FillDown ( GetEndDate, { "Start Date" } ),
                    RemoveNulls = 
                        Table.SelectRows (
                            FillDown,
                            each [End Date] <> null
                        )
                    in 
                        RemoveNulls,
                type table [ Name = text, Start Date = date, End Date = date ]
            }
        }
    ),
    Expand = Table.ExpandTableColumn (
        Group,
        "Count",
        { "Name", "Start Date", "End Date" },
        { "Name", "Start Date", "End Date" }
    ),
    Replace = Table.ReplaceValue ( Expand, "End Date ", "", Replacer.ReplaceText, { "Name" } )
in
    Replace