Why does biblatex-chicago print accessed twice in bibliography?

Question

I am using biblatex-chicago to manage my bibliography but whenever I try to set a bibliography entry with the urldate field, it prints the word 'accessed' twice.

I have created a minimal example to demonstrate the problem. My source document looks like this:

\documentclass[a4paper]{article}
\usepackage[authordate,backend=biber]{biblatex-chicago}
\usepackage[australian]{babel}
\usepackage[babel]{csquotes}
\addbibresource{temp.bib}

\begin{document}

\cite{key}

\vfill\printbibliography

\end{document}

And temp.bib looks like this:

@online{ key,
  author = "Surname, Forename M.",
  title = "Title of an article",
  year = "2012",
  url = "http://www.test.com/",
  urldate = "2012-04-18",
}

When I compile this, I end up with a reference list that looks like this:

Surname, Forename M. 2012. Title of an article. http://www.test.com/
    (accessed [accessed 18 Apr. 2012]).

Can anyone see what is going on? Am I doing something wrong?

Answer 1

It seems the babel is clashing with biblatex-chicago. Pass on the options american or english to babel like \usepackage[english]{babel}. According to biblatex-chicago documentation the option australian is not supported. (Refer section 6, page 95 to explore the possibilities of using australian english (if at all possible)). You need to have, it seems, the appropriate australian.lbx file (which is not supplied by biblatex-chicago by default) to get it working.

With \usepackage[english]{babel}, everything seems to work normally:

\documentclass[a4paper]{article}
\usepackage[authordate,backend=biber]{biblatex-chicago}
\usepackage[english]{babel} % changed the option to english
\usepackage[babel]{csquotes}
\addbibresource{temp.bib}
%
\begin{document}
%
\cite{key}
%\vfill % commented to show things close by. 
\printbibliography
%
\end{document}