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")

Note that :acre could also be 'acre or #:acre or "ACRE"; any string-designator[1] will do. If there are really a few hundred of them then #:acre or "ACRE" has advantages (the other two ways intern symbols).

> 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...