anchor.diff:           (ftype (function * simple-base-string) format-timestring)
            (ftype (function * fixnum) local-timezone)
            (ftype (function * (values
  -                             (integer -43199 43199)
  +                             timezone-offset
                                boolean
                                string)) timestamp-subzone)
            (ftype (function (timestamp &key (:timezone timezone) (:offset (or null integer)))
  
positive.code:   (name "anonymous" :type string)
    (loaded nil :type boolean))
  
  (define-condition invalid-timezone-file (error)
    ((path :accessor path-of :initarg :path))
    (:report (lambda (condition stream)
  
negative.code:                                   (integer -1000000 1000000)
                                    (integer 0 6)
                                    t
                                    timezone-offset
                                    simple-string))
                  decode-timestamp))
  
  