correct leap-p: to use full year

date.lisp

@@ -193,7 +193,7 @@
     (subseq name 0 length)
     name))
 
-(defun date:leap-p (&optional (year (date:year-in-century)))
+(defun date:leap-p (&optional (year (date:year)))
   (and (zerop (mod year 4))
        (or (not (zerop (mod year 100)))
            (zerop (mod year 400)))))