Convert Rows Into Comma Separated Values In A Column SQL Server

DECLARE @COLS    AS NVARCHAR(MAX)

SELECT @COLS = STUFF((SELECT ',' + QUOTENAME(substring(Convert(varchar,D,103),0,3))
from TempAttendRegister
where D >= @startdate
and D <= @enddate
group by D
order by D
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)') 
,1,1,'')