[O] Not a standard Org-mode time string

[Charles Turner]

I'm trying to set up the org-publish system to publish my personal
notes in HTML. My org configuration consists only of

(add-to-list 'load-path "~/src/org-mode/lisp")
(add-to-list 'load-path "~/src/org-mode/contrib/lisp")
(require 'org-publish)
(setq org-publish-project-alist
      '(("notes"
     :base-directory "~/Documents/Notes"
     :publishing-directory "~/Documents/published_notes"
     :base-extension "org"
     :publishing-function org-html-publish-to-html
     :preserve-breaks t
     :with-email nil
     :recursive t
     :auto-sitemap t
     :sitemap-title "Charles' Notes"
     :makeindex t)
    ("notes-static"
     :base-directory "~/Documents/Notes"
     :base-extension "css\\|js\\|jpg\\|gif\\|png\\|svg"
     :publishing-directory "~/Documents/published_notes"
     :publishing-function org-publish-attachment)
    ("charles-notes" :components ("notes" "notes-static"))))

Whilst visiting an org file in my Notes directory, I type M-x
org-publish RET charles-notes and I receive the follow messages in my
*Messages* buffer:

Generating tree-style sitemap for Charles' Notes [6 times]
condition-case: Bad timestamp `Saturday, 28.05.2011 '
Error was: (Not a standard Org-mode time string: Saturday, 28.05.2011 )

I don't understand the time-stamp messages. Can anyone help me debug
this problem?

The system specifics are:
Emacs  : GNU Emacs 24.3.1 (x86_64-pc-linux-gnu, GTK+ Version 3.8.2)
 of 2013-07-27 on roseapple, modified by Debian
Package: Org-mode version 8.2.5h (release_8.2.5h-636-g03514a @
/home/charles/src/org-mode/lisp/)

I'm running from the master branch in git.

Thanks in advance,
Charles.