n format-number(xs:integer(day), '00') else '__'" name="d" as="xs:string"></xxf:variable>
                                            <xxf:variable select="string-join(($y, $m, $d), '-')" name="date-string" as="xs:string"></xxf:variable>
                                            <xf:setvalue ref="is-valid" value="$date-string castable as xs:date"></xf:setvalue>
                                            <xf:setvalue ref="$binding" value="$date-string"></xf:setvalue>
                                      