In author-year citation/bibliography styles, multiple publications by the same author in the same year are formatted with a lowercase letter after the year: Smith 2011a ... Smith 2011b etc.
In biblatex this works fine with numeric dates, but fails with non-numeric dates like "in progress". (The natbib style I use handles these cases correctly by putting parentheses around the letter if the year field is non-numeric.) How do I do the same thing in biblatex? So the expected output is:
Smith, 2011a Smith, 2011b
Smith, in progress(a) Smith, in progress(b)
Sample file and output:
\documentclass{article}
\usepackage[style=authoryear,labelyear=true]{biblatex}
\usepackage{filecontents}
\bibliography{test}
\begin{document}
\cite{test1,test2}
\printbibliography
\begin{filecontents}{test.bib}
@unpublished{test1,
Author = {John Smith},
Date-Added = {2011-02-21 13:41:09 -0500},
Date-Modified = {2011-02-21 13:42:02 -0500},
Note = {ms. MSU},
Title = {A great paper in progress},
Year = {in progress}}
@unpublished{test2,
Author = {John Smith},
Date-Added = {2011-02-21 13:42:09 -0500},
Date-Modified = {2011-02-21 13:42:46 -0500},
Note = {ms. MSU},
Title = {Another great paper in progress},
Year = {in progress}}
\end{filecontents}
\end{document}

labelyear=true, as this is the default for theauthoryearstyle. – lockstep Feb 21 '11 at 19:16