Tikz calendar with week starting on Sunday

Question

I've got a simple Tikz calendar.

I'd just like to start the weeks on Sundays, which seems more natural to me -- that is, I'd like Sundays to be at the left.

Below a MWE:

\documentclass{article}
\usepackage[margin = 2.5cm, a4paper]{geometry}
\pagestyle{empty}
\usepackage[brazil]{babel}
\usepackage{fontspec}
\setmainfont{Alegreya Sans}
\usepackage{tikz}
\usetikzlibrary{calendar,positioning}



\def\pgfcalendarmonthname#1{ \translate{\ifcase#1\or Janeiro\or Fevereiro\or Março\or Abril\or Maio\or Junho\or Julho\or Agosto\or Setembro\or Outubro\or Novembro\or Dezembro\fi} }

    \def\pgfcalendarmonthshortname#1{ \translate{\ifcase#1\or Jan\or Fev\or Mar\or Abr\or Mai\or Jun\or Jul\or Ago\or Set\or Out\or Nov\or Dez\fi} }


\def\pgfcalendarweekdayshortname#1{ \translate{\ifcase#1\or Seg\or Ter\or Qua\or Qui\or Sex\or Sab\or Dom\fi} }

\def\pgfcalendarweekdayname#1{ \translate{\ifcase#1\or Segunda\or Terça\or Quarta\or Quinta\or Sexta\or Sábado\or Domingo\fi} }

\newcommand{\calyear}{2017}
\newcommand{\mon}[1]{\calendar[dates = \calyear-#1-01
    to \calyear-#1-last] if (Sunday) [red];}



\begin{document}
    \begin{tikzpicture}[every calendar/.style = {
        month label above centered,
        month text = {\Large\textsc{\%mt}},
        week list,
    }]
    \matrix (Calendar) [column sep = 4em, row sep = 3em] {
        \mon{01} & \mon{02} & \mon{03} \\
        \mon{04} & \mon{05} & \mon{06} \\
        \mon{07} & \mon{08} & \mon{09} \\
        \mon{10} & \mon{11} & \mon{12} \\ };
    \node [above = 1cm of Calendar, font = \Huge]
    {\calyear};
    \end{tikzpicture}
\end{document}

Answer 1

To integrate macmadness86's answer into the code in the question:

\documentclass{article}
\usepackage[margin = 2.5cm, a4paper]{geometry}
\pagestyle{empty}
\usepackage[brazil]{babel}
\usepackage{fontspec}
\setmainfont{Alegreya Sans}
\usepackage{tikz}
\usetikzlibrary{calendar,positioning}
\makeatletter
\tikzstyle{week list sunday}=[
% Note that we cannot extend from week list,
% the execute before day scope is cumulative
execute before day scope={%
  \ifdate{day of month=1}{\ifdate{equals=\pgfcalendarbeginiso}{}{
      % On first of month, except when first date in calendar.
      \pgfmathsetlength{\pgf@y}{\tikz@lib@cal@month@yshift}%
      \pgftransformyshift{-\pgf@y}
    }}{}%
},
execute at begin day scope={%
  % Because for TikZ Monday is 0 and Sunday is 6,
  % we can't directly use \pgfcalendercurrentweekday,
  % but instead we define \c@pgf@counta (basically) as:
  % (\pgfcalendercurrentweekday + 1) % 7
  \pgfmathsetlength\pgf@x{\tikz@lib@cal@xshift}%
  \ifnum\pgfcalendarcurrentweekday=6
  \c@pgf@counta=0
  \else
  \c@pgf@counta=\pgfcalendarcurrentweekday
  \advance\c@pgf@counta by 1
  \fi
  \pgf@x=\c@pgf@counta\pgf@x
  % Shift to the right position for the day.
  \pgftransformxshift{\pgf@x}
},
execute after day scope={
  % Week is done, shift to the next line.
  \ifdate{Saturday}{
    \pgfmathsetlength{\pgf@y}{\tikz@lib@cal@yshift}%
    \pgftransformyshift{-\pgf@y}
  }{}%
},
% This should be defined, glancing from the source code.
tikz@lib@cal@width=7
]
\makeatother

\def\pgfcalendarmonthname#1{ \translate{\ifcase#1\or Janeiro\or Fevereiro\or Março\or Abril\or Maio\or Junho\or Julho\or Agosto\or Setembro\or Outubro\or Novembro\or Dezembro\fi} }

\def\pgfcalendarmonthshortname#1{ \translate{\ifcase#1\or Jan\or Fev\or Mar\or Abr\or Mai\or Jun\or Jul\or Ago\or Set\or Out\or Nov\or Dez\fi} }

\def\pgfcalendarweekdayshortname#1{ \translate{\ifcase#1\or Seg\or Ter\or Qua\or Qui\or Sex\or Sab\or Dom\fi} }

\def\pgfcalendarweekdayname#1{ \translate{\ifcase#1\or Segunda\or Terça\or Quarta\or Quinta\or Sexta\or Sábado\or Domingo\fi} }

\newcommand{\calyear}{2017}
\newcommand{\mon}[1]{\calendar[dates = \calyear-#1-01
  to \calyear-#1-last] if (Sunday) [red];}

\begin{document}
\begin{tikzpicture}[every calendar/.style = {
    month label above centered,
    month text = {\Large\textsc{\%mt}},
    week list sunday,
  }]
  \matrix (Calendar) [column sep = 4em, row sep = 3em] {
    \mon{01} & \mon{02} & \mon{03} \\
    \mon{04} & \mon{05} & \mon{06} \\
    \mon{07} & \mon{08} & \mon{09} \\
    \mon{10} & \mon{11} & \mon{12} \\ };
  \node [above = 1cm of Calendar, font = \Huge]
  {\calyear};
\end{tikzpicture}
\end{document}

Answer 2

Get started with this Source http://www.texample.net/tikz/examples/changing-the-default-calendar-layout/

Tikz Calendar Style

% Define our own style
    \tikzstyle{week list sunday}=[
        % Note that we cannot extend from week list,
        % the execute before day scope is cumulative
        execute before day scope={%
               \ifdate{day of month=1}{\ifdate{equals=\pgfcalendarbeginiso}{}{
               % On first of month, except when first date in calendar.
                   \pgfmathsetlength{\pgf@y}{\tikz@lib@cal@month@yshift}%
                   \pgftransformyshift{-\pgf@y}
               }}{}%
        },
        execute at begin day scope={%
            % Because for TikZ Monday is 0 and Sunday is 6,
            % we can't directly use \pgfcalendercurrentweekday,
            % but instead we define \c@pgf@counta (basically) as:
            % (\pgfcalendercurrentweekday + 1) % 7
            \pgfmathsetlength\pgf@x{\tikz@lib@cal@xshift}%
            \ifnum\pgfcalendarcurrentweekday=6
                \c@pgf@counta=0
            \else
                \c@pgf@counta=\pgfcalendarcurrentweekday
                \advance\c@pgf@counta by 1
            \fi
            \pgf@x=\c@pgf@counta\pgf@x
            % Shift to the right position for the day.
            \pgftransformxshift{\pgf@x}
        },
        execute after day scope={
            % Week is done, shift to the next line.
            \ifdate{Saturday}{
                \pgfmathsetlength{\pgf@y}{\tikz@lib@cal@yshift}%
                \pgftransformyshift{-\pgf@y}
            }{}%
        },
        % This should be defined, glancing from the source code.
        tikz@lib@cal@width=7
    ]

Replace your style week list with week list sunday.

Answer 3

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calendar, positioning}
\usepackage{xparse}
\NewDocumentCommand\mon{m O{\the\year}}
{
    \calendar[
        dates=#2-#1-1 to #2-#1-last, % date range
        month label above centered, % month lable alignment
        % get month short name
        month text = {\textit{\pgfcalendarmonthshortname{\pgfcalendarcurrentmonth}}},
        % if Sunday shift to left 1.5em otherwise move to the right 1.5em * weekday code (Monday = 0, ..., Saturday=6)
        execute at begin day scope={ \ifdate{Sunday}{\pgftransformxshift{-1.5em}}{\pgftransformxshift{1.5*\pgfcalendarcurrentweekday em}}},
        % if Saturday move down 1.2em to another line
        execute after day scope={\ifdate{Saturday}{\pgftransformyshift{-1.2em}}{}},
        % adjust month lable to the center
        every month/.append style={xshift=3em},
        % mark today
        execute at begin day scope={\ifdate{equals=\year-\month-\day}{\draw[fill=green!30] (0,0) circle (8pt);}{}}]
    if(Sunday) [red!50!black]
    if(Saturday) [red!50!black];
}

\begin{document}
\begin{tikzpicture}[every day/.style={anchor=mid}]
    \matrix (Calendar) [column sep = 2em, row sep = 3em] {
        \mon{01} & \mon{02} & \mon{03}                          \\
        \mon{04} & \mon{05} & \mon{06}                          \\
        \mon{07} & \mon{08} & \mon{09}                          \\
        \mon{10} & \mon{11} & \mon{12} \\};
    \node [above=of Calendar, font=\Huge]{\the\year};
\end{tikzpicture}

\end{document}