TikZ calendar: stretching day list to exactly the linewidth

Question

I'd like to create a wall calendar where the bottom of each page is a tikzpicture, stretching the list of days always to the \linewidth, as if it was justified text.

How can I set a calendar style that will xshift the days just so? I got as far as you can see below, but since day xshift={0.0322\linewidth} is fixed, it only works for 31 day months.

\documentclass[11pt]{article}

\usepackage[showframe]{geometry}

\usepackage{tikz}
\usetikzlibrary{calendar}

\setlength{\parindent}{0pt}
\pagestyle{empty}

\definecolor{gold}{RGB}{199,147,22}

\begin{document}

\raggedright

\makeatletter

\tikzset{
  every calendar/.style={
    day list right,
    day xshift={0.0322\linewidth},
    month text={\color{gold}\%mt \%y0},
    month label above left,
    execute at begin day scope={
      \ifdate{Sunday}{\color{red}}
    }
  }
}

\makeatother

\raggedright

\tikz\calendar[dates=2013-01-01 to 2013-01-last];
\tikz\calendar[dates=2013-02-01 to 2013-02-last];
\tikz\calendar[dates=2013-03-01 to 2013-03-last];
\tikz\calendar[dates=2013-04-01 to 2013-04-last];
\tikz\calendar[dates=2013-05-01 to 2013-05-last];

\end{document}

Answer 1

You can use the execute after day scope to execute some code to extract the number of days in the current month and perform a \pgftransformxshift accordingly:

\documentclass[11pt]{article}

\usepackage[showframe]{geometry}

\usepackage{tikz}
\usetikzlibrary{calendar}

\setlength{\parindent}{0pt}
\pagestyle{empty}

\definecolor{gold}{RGB}{199,147,22}

\begin{document}

\raggedright


\tikzset{
  every calendar/.style={
    day list right,
    day xshift={0pt},
    month text={\color{gold}\%mt \%y0},
    month label above left,
    execute at begin day scope={
      \ifdate{Sunday}{\color{red}}
    },
    execute after day scope=   
    {
      \pgfcalendarjuliantodate{\pgfcalendarendjulian}{\currentyear}{\currentmonth}{\lastday}
      \pgftransformxshift{\textwidth/\lastday}
    }
  }
}



\tikz\calendar[dates=2013-01-01 to 2013-01-last];
\tikz\calendar[dates=2013-02-01 to 2013-02-last];
\tikz\calendar[dates=2013-03-01 to 2013-03-last];
\tikz\calendar[dates=2013-04-01 to 2013-04-last];
\tikz\calendar[dates=2013-05-01 to 2013-05-last];

\end{document}

If you want the space between each day to be equal (which looks much nicer in this case), a little more calculation is needed:

\documentclass[11pt]{article}

\usepackage[showframe]{geometry}

\usepackage{tikz,calc}
\usetikzlibrary{calendar}

\setlength{\parindent}{0pt}
\pagestyle{empty}

\definecolor{gold}{RGB}{199,147,22}

\begin{document}

\raggedright
\makeatletter
\tikzset{
  every calendar/.style={
    day list right,
    day xshift={0pt},
    month text={\color{gold}\%mt \%y0},
    every month/.append style={inner xsep=0pt},
    every day/.append style={anchor=east, inner xsep=0pt},
    month label above left,
    if=(Sunday) [red],
    execute before day scope={
    \ifdate{day of month=1}{
        \pgftransformxshift{-\widthof{01}}
    }{
            \pgfcalendarjuliantodate{\pgfcalendarendjulian}{\currentyear}{\currentmonth}{\lastday}
        \pgfmathparse{(\textwidth-\widthof{123456789}-\widthof{10111213141516171819202122232425262728}-\widthof{30}*(\lastday-28))/(\lastday-1)}
        \pgftransformxshift{\pgfmathresult}     
        \let\%=\pgfcalendarshorthand
        \setlength{\pgf@xc}{\widthof{\%d-}}
        \pgftransformxshift{\pgf@xc}
        }
    }
  }
}



\tikz\calendar[dates=2013-01-01 to 2013-01-last];
\tikz\calendar[dates=2013-02-01 to 2013-02-last];
\tikz\calendar[dates=2013-03-01 to 2013-03-last];
\tikz\calendar[dates=2013-04-01 to 2013-04-last];
\tikz\calendar[dates=2013-05-01 to 2013-05-last];
\end{document}