Get Name of days between tow dates in sql server

//           Create function

Create FUNCTION [dbo].[Get_NameOf_Days](

@startdate datetime

,@enddate datetime

,@DayValue int -- return the value of days (starting day with sunday- value=1)

,@NameValue int -- return the name of days (starting day with monday- value=0)

)

RETURNS VARCHAR(MAX)

BEGIN

declare @count int =0

    while @startdate<=@enddate

    Begin

        IF DatePart(WEEKDAY,@startdate) = @DayValue

            SET @count=@count+1

        SET @startdate=DateAdd(d,1,@startdate)

    END

RETURN  (select DATENAME(dw,@NameValue)+' : '+CAST(@count as varchar))

END

//           Call  function

select dbo.Get_NameOf_Days('2017-1-1','2017-1-31',1,6)

//           Result