Gist for the question https://tex.stackexchange.com/q/395330/117727

timetable.tex

% %%%%%%%%%%%%%%
% Document setup
% %%%%%%%%%%%%%%

\documentclass[10pt,a4paper, landscape, german]{article}
\usepackage[T1]{fontenc}
\usepackage{babel}
\usepackage{translator}

% Page layout
\usepackage[headheight = 11ex, margin = .5cm, top = 3cm, nofoot, showframe = true]{geometry}
\usepackage{fancyhdr}

% Fonts
\usepackage{lmodern}
\renewcommand*\familydefault{\sfdefault}

% Drawing
\usepackage{tikz}
\usetikzlibrary{shapes}
\usetikzlibrary{fit}
\usepackage{pgfcore}
\usepackage{pgfcalendar}

% Logic and Tools
\usepackage{environ}
\usepackage{calc}



% %%%%%%%%%
% Variables
% %%%%%%%%%

\newcommand\currentyear{2017}

% Colors
\definecolor{primary}{HTML}{00CC00}

\definecolor{FKSem}{HTML}{84D4BC}
\definecolor{FKVor}{HTML}{A1DECC}
\definecolor{MolSem}{HTML}{BB84D5}
\definecolor{MolVor}{HTML}{CCA1DE}
\definecolor{OrgSem}{HTML}{D4BC84}
\definecolor{OrgVor}{HTML}{DECCA1}
\definecolor{Prak}{HTML}{B7C0D5}

% Author
\author{Sam Thilmany}

% Set the first and last hour of the day (24h day format)
\newcommand{\firstH}{8}
\newcommand{\lastH}{20}



% %%%%%%%%%%%%
% Calculations
% %%%%%%%%%%%%

% Add 1 to \currentyear to define \nextyear
\edef\nextyear{\the\numexpr\currentyear+1\relax}

% Converts a given time (hh.mm) to a length. \firstH is converted to 0.
\pgfmathdeclarefunction{time}{1}{%
	\pgfmathparse{\firstH-(floor(#1)+(#1-floor(#1))/0.6)}%
}



% %%%%%%
% Header
% %%%%%%

\renewcommand{\headrulewidth}{0pt}
\fancyhf{}
\lhead{%
    \fontsize{60}{70}\selectfont\bfseries{%
        WS \currentyear/\nextyear
    }
}
\pagestyle{fancy}



% %%%%%%%%%%%%%%%%%%%%%%%
% Macros and Environments
% %%%%%%%%%%%%%%%%%%%%%%%

% Macro for drawing calendar entries
\newcommand{\calentry}[7]{
	\path
		(#1 - 0.75, {time(#2)}) coordinate (A)
		(#1 + 0.25, {time(#3)}) coordinate (B);

	\draw [draw = none] (A) rectangle (B);

	\node [
        fit = {(A) (B)},
        inner sep = 0,
        fill = #6,
		draw = black,
        text = #7,
        text width = \entrytextwidth,
        text centered,
    ]
    {
        \small{\textbf{#4}}
        \\
        \footnotesize{#5}
    };
}

% Timetable environment
\NewEnviron{timetable}%
	{%
        \begin{tikzpicture}[x = \widthofday, y = \lengthofhour]

            % Draws the timtables grid
            \foreach \hour in {\firstH, ..., \lastH}{
                \node[
                    minimum height = .53cm,
                    text width = \entrytimewidth,
                    draw = primary
                ] at (0, \firstH - \hour) {\hour:00};
            }

            \foreach \day in {0, ..., 4} {
                \node[
                    minimum height = .53cm,
                    text width = \entrytextwidth,
                    fill = primary,
                    text = white,
                    draw = primary,
                    text centered
                ] at (\day + 0.75, 1) {\pgfcalendarweekdayname{\day}};

                \foreach \hour in {\firstH, ..., \lastH}{
                    \draw (\day + 0.25, \firstH - \hour) -- (\day + 1.25, \firstH - \hour);
                }
            }

            {\BODY}

        \end{tikzpicture}
	}%



% %%%%%%%%%%%%%%
% Begin Document
% %%%%%%%%%%%%%%

\begin{document}
	\newlength{\basewidth}
	\setlength{\basewidth}{2\columnwidth/11}

	\newlength{\widthofday}
	\setlength{\widthofday}{\basewidth}

	\newlength{\entrytextwidth}
	\setlength{\entrytextwidth}{\widthofday}
	\addtolength{\entrytextwidth}{-0.4cm}

	\newlength{\timewidth}
	\setlength{\timewidth}{.5\basewidth}

	\newlength{\entrytimewidth}
	\setlength{\entrytimewidth}{\timewidth}
	\addtolength{\entrytimewidth}{-0.4cm}

	\newlength{\lengthofhour}
	\setlength{\lengthofhour}{1.25cm}

    \centering
    \begin{timetable}
        % Monday
        \calentry{1}{10.00}{10.45}{FK-Chemie}{Seminar}{FKSem}{black}
        \calentry{1}{11.00}{11.45}{FK-Chemie}{Vorlesung}{FKVor}{black}
        \calentry{1}{12.00}{12.45}{Org. Chemie}{Vorlesung}{OrgVor}{black}

        % Tuesday
        \calentry{2}{10.15}{11.00}{Mol.-Chemie}{Seminar}{MolSem}{black}
        \calentry{2}{11.15}{12.00}{FK-Chemie}{Vorlesung}{FKVor}{black}
        \calentry{2}{12.15}{13.00}{Org. Chemie}{Vorlesung}{OrgVor}{black}

        \calentry{2}{13.45}{19.45}{Mol.- \& FK-Chemie}{Praktikum}{Prak}{black}

        % Wednesday
        \calentry{3}{11.15}{12.00}{Mol.-Chemie}{Vorlesung}{MolVor}{black}
        \calentry{3}{12.15}{13.00}{Org. Chemie}{Vorlesung}{OrgVor}{black}

        \calentry{3}{14.00}{20.00}{Mol.- \& FK-Chemie}{Praktikum}{Prak}{black}

        % Thursday
        \calentry{4}{8.15}{9.00}{Org. Chemie}{Seminar}{OrgSem}{black}
        \calentry{4}{12.15}{13.00}{Org. Chemie}{Vorlesung}{OrgVor}{black}

        \calentry{4}{14.00}{20.00}{Mol.- \& FK-Chemie}{Praktikum}{Prak}{black}

        % Friday
        \calentry{5}{8.15}{9.00}{Mol.-Chemie}{Vorlesung}{MolVor}{black}
    \end{timetable}
\end{document}