Define a list of dates for tikz calendars

calendartex-coretikz-calendartikz-pgf

I am trying to pass a list of dates to a calendar using a pgf key, so that I can use it in different parts of the code.

Follow the PGF & TIKZ manual, I got it for mybirthday (see code below).
However, a similar idea does not work in myholidays. How can i fix it?
By the way, is there a better solution to define a "list" (or array, etc) of dates to achieve it?

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{calendar}

\newcommand\myweekdayname[1]{\ifcase#1M\or T\or W\or T\or F\or S\or S\fi}

\pgfkeys{/pgf/calendar/mybirthday/.code={
    \ifnum\pgfcalendarifdatemonth=1\relax
        \ifnum\pgfcalendarifdateday=20\relax
            \pgfcalendarmatchestrue
        \fi\fi}}

\pgfkeys{/pgf/calendar/myholidays/.code={
    \foreach \m / \d in {1/4, 1/5, 1/6, 1/7, 1/8}{
        \ifnum\pgfcalendarifdatemonth=\m\relax
            \ifnum\pgfcalendarifdateday=\d\relax
                \pgfcalendarmatchestrue
            \fi\fi}}}

\begin{document}

\begin{tikzpicture}
    \calendar[
        dates=2021-01-01 to 2021-01-last,
        day list downward, day yshift = 1em,
        day code={
            \ifdate{weekend, mybirthday, myholidays}{
                \node[shape=coordinate]{}; % trick (1)
                }{
                \node[anchor = east]{\tikzdaytext};
                \node[anchor = west, gray]{\myweekdayname{\pgfcalendarcurrentweekday}};
                }},
        execute after day scope={
            \ifdate{weekend, mybirthday, myholidays}{\pgftransformyshift{1em}}{};
            \ifdate{Sunday}{\pgftransformyshift{-0.5em}}{} % week skip
            }       
        ];
\end{tikzpicture}

\end{document}

(1) Calendar with TikZ; only print week days

Best Answer

The loop body of \foreach is enclosed in a group, so changes with \let, \def and derived commands stay local, are forgotten at the end of the loop.

Since \pgfcalendarmatchestrue is defined as \let \ifpgfcalendarmatches \iftrue, it suffices to add \global in front:

\pgfkeys{/pgf/calendar/myholidays/.code={
    \foreach \m / \d in {1/4, 1/5, 1/6, 1/7, 1/8}{
        \ifnum\pgfcalendarifdatemonth=\m\relax
            \ifnum\pgfcalendarifdateday=\d\relax
                \global\pgfcalendarmatchestrue
            \fi\fi}}}
Related Question