Пример работы со временем в коде

(defconstant *day-names*
    '("Monday" "Tuesday" "Wednesday"
      "Thursday" "Friday" "Saturday"
      "Sunday"))
; *DAY-NAMES*

(multiple-value-bind
        (second minute hour date month year day-of-week dst-p tz)
        (get-decoded-time)
    (format t "It is now ~2,'0d:~2,'0d:~2,'0d of ~a, ~d/~2,'0d/~d (GMT~@d)"
              hour
              minute
              second
              (nth day-of-week *day-names*)
              month
              date
              year
              (- tz)))
; It is now 17:07:17 of Saturday, 1/26/2002 (GMT-5)