Count selected day between dates

Parameter
Value
WeekDay
Count
StartDate
25/05/2020
 Monday
4
EndDate
15/06/2020


Code:
// WeekDay
let
    Source = Excel.CurrentWorkbook(){[Name="WeekDay"]}[Content],
    Type = Table.TransformColumnTypes(Source,{{"WeekDay", type text}})
in
    Type

// fnGetParameter
(ParameterName as text) =>
    let
        ParamSource = Excel.CurrentWorkbook(){[Name="Parameters"]}[Content],
        ParamRow = Table.SelectRows(ParamSource, each ([Parameter]=ParameterName)),
            Value=
            if Table.IsEmpty(ParamRow)=true
                        then null
                        else Record.Field(ParamRow{0},"Value")
    in
        Value

// Calendar
let
    startdate = Number.From(fnGetParameter("StartDate")),
    enddate = Number.From(fnGetParameter("EndDate")), 

    Source = {startdate..enddate},
    ToTable = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
    Type = Table.TransformColumnTypes(ToTable,{{"Column1", type date}}),
    DayName = Table.AddColumn(Type, "Day Name", each Date.DayOfWeekName([Column1]), type text)
in
    DayName

// Merge1
let
    Source = Table.NestedJoin(WeekDay,{"WeekDay"},Calendar,{"Day Name"},"Calendar",JoinKind.LeftOuter),
    Expand = Table.ExpandTableColumn(Source, "Calendar", {"Day Name"}, {"Day Name"}),
    Group = Table.Group(Expand, {"Day Name"}, {{"Count", each Table.RowCount(_), type number}}),
    TSC = Table.SelectColumns(Group,{"Count"})
in
    TSC