anchor.diff:    (let ((local-time (make-local-time
                        :day (- (random 65535) 36767)
                        :sec (random 86400)
  -                     :usec (random 1000))))
  +                     :nsec (random 1000))))
       (multiple-value-bind (ms ss mm hh day mon year) (decode-local-time local-time)
         (is (local-time= local-time (encode-local-time ms ss mm hh day mon year))))))
   
  
positive.code: (test format-timestring
    (is-every string=
      "2008-06-05T04:03:02.000001"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-timezone-part-p t)
  
      "2008-06-05T04:03:02.000001-05:00"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008
                                            :timezone (local-time::make-timezone
                                                       :subzones `((,(* (* 60 5) -60) nil "anonymous" nil nil))
                                                       :loaded t)))
  
      "2008-06-05T04:03:02.000001Z"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008 :timezone +utc-zone+) :use-zulu-p t)
  
      "2008-06-05T04:03:02.12345678+00:00"
      (format-timestring (encode-local-time 12345678 2 3 4 5 6 2008 :timezone +utc-zone+) :use-zulu-p nil)
  
      "-06-05T04:03:02.000001"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-timezone-part-p t :date-elements 2)
  
      "-05T04:03:02.000001"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-timezone-part-p t :date-elements 1)
  
      "04:03:02.000001"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-timezone-part-p t :omit-date-part-p t)
  
      "04:03:02"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-timezone-part-p t :omit-date-part-p t :time-elements 3)
  
      "-0005-06-05T04:03:02.000001"
      (format-timestring (encode-local-time 1 2 3 4 5 6 -5) :omit-timezone-part-p t)
  
      ""
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-time-part-p t :omit-date-part-p t)
  
      "04"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-timezone-part-p t :omit-date-part-p t :time-elements 1)
  
      "04:03"
      (format-timestring (encode-local-time 1 2 3 4 5 6 2008) :omit-timezone-part-p t :omit-date-part-p t :time-elements 2)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  
negative.code: 
  (test read-universal-time
    (let ((now (now)))
      (setf (nsec-of now) 0)
      (is (local-time= now
                       (with-input-from-string (ins (princ-to-string (universal-time now)))
                         (local-time::read-universal-time ins #\@ nil))))))
  