let
Source = {42500 .. 48000},
Converted_to_Table = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
Chg_to_Date = Table.TransformColumnTypes(Converted_to_Table,{{"Column1", type date}}),
Renamed = Table.RenameColumns(Chg_to_Date,{{"Column1", "Date"}}),
AddCol_Mois = Table.AddColumn(Renamed, "Mois ", each Text.BetweenDelimiters(Text.From([Date], "fr-BE"), "-", "-"), type text),
AddCol_Annee = Table.AddColumn(AddCol_Mois, "Année", each Date.Year([Date]), Int64.Type),
Added_temp_Date = Table.AddColumn(AddCol_Annee, "date temp", each Date.AddMonths([Date] , -3 )),
AddCol_MoisComptable = Table.AddColumn(Added_temp_Date, "Mois Comptable", each Text.BetweenDelimiters(Text.From([date temp], "fr-BE"), "-", "-"), type text),
AddCol_AnnéeComptable = Table.AddColumn(AddCol_MoisComptable, "Année Comptable", each Date.Year([date temp]), Int64.Type),
Change_type = Table.TransformColumnTypes(AddCol_AnnéeComptable,{{"Année", type text}, {"Année Comptable", type text}}),
Delete_unusedCol = Table.RemoveColumns(Change_type,{"date temp"})
in
Delete_unusedCol