%% 
%%  A DANTE-Edition example
%% 
%%  Example 06-00-25 on page 191.
%% 
%%  Copyright (C) 2010 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{177.70511pt}
\setlength\parindent{0pt}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{tabularx,longtable,amsmath}
\usepackage[table]{xcolor}
\newcommand*\RMarker{.}
\newcommand*\SeminarOn[1][Weekend]{%
  \def\RMarker{\rbrace\text{#1}}}
\newcommand*\SeminarOff{\def\RMarker{.}}
\newcommand*\SA{\rowcolor{black!20}}
\newcommand*\SO{\rowcolor{black!30}}

\begin{document}
\begin{longtable}{>{$\left.}l<{\right\RMarker$}}
\SeminarOn[Seminar]
\begin{tabularx}{.6\linewidth}{rlX}
  2 & Tu & \\ 3 & We & \\
  4 & Th & \\ 5 & Fr & \\
\end{tabularx} \\\SeminarOn
\begin{tabularx}{.6\linewidth}{rlX}
\SA 6 & Sa & round table\\
\SO 7 & So & \\
\end{tabularx} \\\SeminarOff
\begin{tabularx}{.6\linewidth}{rlX}
    8 & Mo &\\  9 & Tu &
\end{tabularx}
\end{longtable}
\end{document}