\documentclass[a4paper,fleqn,11pt]{article}
\usepackage[T1]{fontenc}
\usepackage[english,naustrian,american,ngerman,num]{isodate}
%\usepackage{ngerman}
\usepackage[english,naustrian,american,ngerman]{babel}
%\usepackage{bibgerm}

\setlength{\parindent}{0mm}

\newcommand{\example}[1]{%
  \selectlanguage{#1}
%  \ifthenelse{\equal{#1}{american}}{\dateamerican}{}%
  \section*{Language: \languagename}
  \begin{tabular}{@{}lll}
    today&normal date format&\origdate\today\\
    &isodate&\isodate\today\\
    &numdate&\numdate\today\\
    &shortdate&\shortdate\today\\
    &TeXdate&\TeXdate\today\\
    &back to normal&\origdate\today\\
    another day&normal date format&\origdate\printdate{1972-1-30}\\
    &isodate&\isodate\printdate{30.1.1972}\\
    &numdate&\numdate\printdate{1972-1-30}\\
    &shortdate&\shortdate\printdate{1972-1-30}\\
    &TeXdate&\TeXdate\printdate{1972-1-30}\\
    &back to normal&\origdate\printdate{30/1/1972}\\
  \end{tabular}}
\begin{document}
\today

%\monthyearsepgerman{\qquad}{\quad}%
%\daymonthsepgerman{\quad}%

\example{\ngerman}
\example{\naustrian}
\example{\english}
%\example{\USenglish}
\example{\american}

\section*{Changed ISO output}
\isodate
\printdate{24/12/2000}

\isodash{--}
\printdate{24/12/2000}

\isodash{$\cdot$}
\printdate{24.12.2000}

\end{document}

