[pgfgantt] Deutsch mit polyglossia?

Mit polyglossia funktioniert das leider nicht. Wie ging es mit polyglossia?

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
\documentclass{scrartcl}
\usepackage{pgfgantt}
\usetikzlibrary{shadows}
\usetikzlibrary{shadings}
\usetikzlibrary{shapes}
\usepackage{xltxtra}
\defaultfontfeatures{Mapping=tex-text}
\usepackage{polyglossia}
\setdefaultlanguage[spelling=new]{german}
\begin{document}
\begin{ganttchart}
    [
    x unit=1mm,
    time slot format=isodate]
    {2013-09-22}{2014-01-19}
    \gantttitlecalendar{year, month=shortname}
\end{ganttchart}
\end{document}
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX