(defun days-since (day month year)
 "Returns number of days since start of the year."
 (let ((days (+ day (* (1- month) 30))))
   (incf days
         (if (>= month 9)
             (1+ (floor (/ month 2)))
             (floor (/ month 2))))
   (if (and (zerop (rem year 4))
            (if (zerop (rem year 100))
                (zerop (rem year 400))
                t))
       (decf days)
       (decf days 2))
   days))

(defun programmers-day-p (&key pretty-print)
 "Is it Programmer's Day?"
 (let* ((time (get-universal-time))
        (day (fourth #1=(multiple-value-list
                         (decode-universal-time time))))
        (month (fifth #1#))
        (year (sixth #1#)))
   (if (eql (days-since day month year) 256)
       (progn (if pretty-print
                  (format t
                          "~%you're a pathetic loser on programmer's day.~%"))
              t)
       (progn (if pretty-print
                  (format t
                          "~%you really are a pathetic…