This is the copyright notice from the original Lisp code

;;;;
;;;; CALENDRICA 4.0 -- Common Lisp
;;;; E. M. Reingold and N. Dershowitz
;;;;
;;;; ================================================================
;;;;
;;;; The Functions (code, comments, and definitions) contained in this
;;;; file (the "Program") were written by Edward M. Reingold and Nachum
;;;; Dershowitz (the "Authors"), who retain all rights to them except as
;;;; granted in the License and subject to the warranty and liability
;;;; limitations listed therein.  These Functions are explained in the Authors'
;;;; book, "Calendrical Calculations", 4th ed. (Cambridge University
;;;; Press, 2016), and are subject to an international copyright.
;;;;
;;;; Licensed under the Apache License, Version 2.0 <LICENSE or
;;;; https://www.apache.org/licenses/LICENSE-2.0>.
;;;;
;;;; Sample values for the functions (useful for debugging) are given in
;;;; Appendix C of the book.

;;;; Last modified 20 December 2016.

#### The Lisp code was ported to R by Rob Hyndman.
#### Reingold and Dershowitz are not responsible for any errors introduced
#### in the process of translating the code from Lisp to R.
