What's wrong with this elisp code?

[ken]

This line below is in a script:

emacs --batch emacs-diary-day >& /home/xxx/tmp/emacs-diary-log

In /usr/share/emacs/21.3/site-lisp/ (confirmed in load-path) is a file
entitled emacs-diary-day.el; this file contains:

;show today's entries only
(diary 1)
(find-file "/home/xxx/tmp/emacs-diary-day")
;erase everything that might be in the buffer
(erase-buffer)

;see below for the arg to insert
;(apply 'insert diary-entries-list)
;tried both the above and below. Same error either way
(insert diary-entries-list)
(save-buffer)



I found this documentation earlier today:

the variable `diary-entries-list' is a list, in order by date, of all
relevant diary entries in the form of ((MONTH DAY YEAR) STRING), where
string is the diary entry for the given date.  This can be used, for
example, a different buffer for display (perhaps combined with
holidays), or produce hard copy output.

But I'm getting the error:

Loading rng-auto.el (source)...
Loading /usr/lib/emacs/21.3/i586-suse-linux/fns-21.3.1.el (source)...
Preparing diary...
Preparing diary...done
Symbol's value as variable is void: diary-entries-list

If I (setq diary-entries-list "Some string of chars")
there's no error, but of course this isn't what I'm after.

Any happy tips?