SDF's 25th anniversary
       Saturday Jun 16  5:11:46 2012
       
       ;; sdf.lisp - In honor of 25 years of SDF, and my common lisp class
       
       (defun ones (x)
         (if (< x 10) x
                      (ones (- x 10))))
       
       (defun num-suffix (x)
         (cond ((= x 1) "st")
               ((= x 2) "nd")
               ((= x 3) "rd")
               (t "th")))
       
       (defun print-ann (year suffix)
         (format t "Happy ~S~a anniversary SDF!!!" year suffix))
       
       (defun print-oper (year month day)
         (if (or (< day 16) (< month 6)) (format t "SDF has been in operation for ~S ye
                                         (format t "SDF has been in operation for ~s ye
       
       (defun sdf ()
         (setf time (multiple-value-list (get-decoded-time)))
         (setf cur-year (sixth time))
         (setf month (fifth time))
         (setf day (fourth time))
         (setf anniversary (- cur-year 1987))
         (if (and (= month 6) (= day 16)) (print-ann anniversary (num-suffix (ones anni
                                          (print-oper anniversary month day)))
       
       (sdf)