Grouping by Consecutive Dates and Category

johnfa it was an interesting question, 
you can solve it by copy the below code and past it into the advaance editor.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUTIw1AciIwMjEyDHGMGJ1UHIGyPLG2PKm8DkjSzgHJi8kSWSPEixGaZ+C5i8AljYiYCznFBNAtqBZGwsAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Category = _t, #"Start Date" = _t, #"End Date" = _t]),
    #"Changed Type1" = Table.TransformColumnTypes(Source,{{"Category", type text}, {"Start Date", type date}, {"End Date", type date}}),
    #"Grouped Rows" = Table.Group(#"Changed Type1", {"Category"}, {{"Count", each  [a=Table.ToRows(_[[Start Date],[End Date]]),b=List.Accumulate(List.Skip(List.Positions(a)),{1},(x,y)=> if a{y}{0}=a{y-1}{1}+Duration.From(1) then x&{List.Last(x)} else x &{ List.Last(x)+1}), c=Table.AddIndexColumn(_,"in",0,1),d=Table.AddColumn(c,"Grouping",(m)=> b{m[in]})  ][d]}}),
    #"Expanded Count" = Table.ExpandTableColumn(#"Grouped Rows", "Count", {"Category", "Start Date", "End Date", "in", "Grouping"}, {"Category.1", "Start Date", "End Date", "in", "Grouping"})
in
    #"Expanded Count"