Try move a one space near at your "%) and I corrected the query. Try to figure out.
Dim strSQL As String = "SELECT EMP_ID,EMP_NAME,AT_STATUS, " + _ "AT_REMARK FROM ATTENDANCE " + _ "WHERE Convert(Varchar(10), AT_DATE, 23) = " + _ "('" & editdate.ToString("yyyy-MMM-dd") & "') ORDER BY EMP_NAME ASC"