They probably want to replace the header of calendar.l with something roughly like:

  (defpackage "CC4"
    (:use "COMMON-LISP")
    (:export 
     :acre
     :advent
     :akan-day-name
     :akan-day-name-on-or-before

     [and so on for a few hundred lines]
  
     :yom-ha-zikkaron
     :yom-kippur
     :zone
    ))
  
  (in-package "CC4")

> believe the problem with the unedited code has something to do with packages and namespaces

Since "package" is what Common Lisp calls namespaces, the "and namespaces' is redundant, but the general thrust is correct.

1: https://www.lispworks.com/documentation/HyperSpec/Body/26_gl...