added values expression

isodate.lisp

@@ -160,9 +160,10 @@
   (declare (integer date))
   (multiple-value-bind (second minute hour date month year day daylight-p zone) (decode-universal-time date)
     (declare (ignorable day daylight-p zone))
-    (format nil "~4,'0d-~2,'0d-~2,'0dT~2,'0d:~2,'0d:~2,'0d"
-            year month date
-            hour minute second)))
+    (values (format nil "~4,'0d-~2,'0d-~2,'0dT~2,'0d:~2,'0d:~2,'0d"
+                    year month date
+                    hour minute second)
+            date)))
 
 (defun date-stamp ()
   (values (print-date (get-universal-time))