A full year calendar in A1 paper size, showing US holidays.

Latex-Full-Year-Calendar.tex

% DIN-A1 year calendar
% Author: Robert Krause
% Modified by: Sérgio Jardim (@sjardim)
% License : Creative Commons attribution license
% Submitted to TeXample.net on 13 July 2012
\documentclass[landscape,a1paper,21pt]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{tikz} 			% Use the calendar.sty style

\usepackage{fancyhdr}		% header and footer
\usepackage{fix-cm}		% Large year in header

\usepackage[landscape, headheight = 1cm, margin=0cm,
  top = 1.2cm, nofoot]{geometry}
\usetikzlibrary{calc}
\usetikzlibrary{calendar}

\usepackage{verbatim}

\title{Full Year Calendar with Holidays}
\author{jardim.sergio }
\date{December 2024}


\usepackage{PTSansNarrow}
\renewcommand*\familydefault{\sfdefault}

%========= INSTRUCTIONS ============================================

% TO EDIT THE CALENDAR, FOLLOW THE #NUMBERED STEPS (ONLY 3)
% IGNORE THE OTHER SETTINGS UNLESS YOU KNOW WHAT YOU'RE DOING :)
% LINES 32, 55 AND 87

% #01 Set the base year
% \def\year{2025}
\def\calendaryear{2025}
\edef\nextcalendaryear{\number\numexpr\calendaryear+1}

% Names of Holidays are inserted by employing this macro
\def\holiday#1#2{
  \node [anchor=north west, text width= 5.9cm] at
    ($(cal-#1.north west)+(0em, 0em)$) {\tiny{#2}};
}

%Header
\renewcommand{\headrulewidth}{0.0pt}
\setlength{\headheight}{10ex}
%\chead{}
%Footer
\cfoot{\footnotesize\texttt{}}

\definecolor{titlescolor}{RGB}{79,23,168}
\definecolor{holidaycolor}{RGB}{230,208,255}

\begin{document}
\pagestyle{fancy}
\begin{center}
\begin{tikzpicture}[every day/.style={anchor = north}]

\calendar[
% #02 Set the months period (that will appear as columns)
  dates=2025-01-01 to 2026-01-31,
  name=cal,
  day yshift = 1em,
  day code=
  {
    \node[name=\pgfcalendarsuggestedname,every day,shape=rectangle,
    minimum height= 1.7cm, text width = 5.9cm, draw = black]{\hskip-.15cm\bfseries\tikzdaytext};
    \draw (-9ex, -1.4ex) node[anchor = west]{\tiny%
      \pgfcalendarweekdayshortname{\pgfcalendarcurrentweekday}};
  },
  execute before day scope=
  {
    \ifdate{day of month=1}
    {
      % Shift right
      \pgftransformxshift{6.4cm}
      % Print month name 
      \draw (0,-.2ex)node [shape=rectangle, minimum height= 1cm,
        text width = 5.9cm, fill = titlescolor, text= white, draw = titlescolor, text centered]
        {\MakeUppercase{\large\textbf{\pgfcalendarmonthname{\pgfcalendarcurrentmonth}\strut}}};
    }{}
    \ifdate{workday}
    {
      % normal days are white
      \tikzset{every day/.style={fill=none}}      
    }{}
    % Saturdays
    \ifdate{Saturday}{\tikzset{every day/.style={fill=black!10}}}{}
    % Sundays
    \ifdate{Sunday}{\tikzset{every day/.style={fill=black!20}}}{}
       % Federal Holidays
    \ifdate{equals=\calendaryear-01-01}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-01-20}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-02-17}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-05-26}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-06-19}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-07-04}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-09-01}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-10-13}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-11-11}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-11-27}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\calendaryear-12-25}{\tikzset{every day/.style={fill=holidaycolor}}}{}
    \ifdate{equals=\nextcalendaryear-01-01}{\tikzset{every day/.style={fill=holidaycolor}}}{}
},
 execute at begin day scope=
  {
    % each day is shifted down according to the day of month
    \pgftransformyshift{-1.7*\pgfcalendarcurrentday cm}
  }
];

% Print name of Holidays
\holiday{\calendaryear-01-01}{New Year's Day}
\holiday{\calendaryear-01-20}{Martin Luther King Jr. Day}
\holiday{\calendaryear-02-17}{Presidents' Day}
\holiday{\calendaryear-05-26}{Memorial Day}
\holiday{\calendaryear-06-19}{Juneteenth}
\holiday{\calendaryear-07-04}{Independence Day}
\holiday{\calendaryear-09-01}{Labor Day}
\holiday{\calendaryear-10-13}{Columbus Day}
\holiday{\calendaryear-11-11}{Veterans Day}
\holiday{\calendaryear-11-27}{Thanksgiving Day}
\holiday{\calendaryear-12-25}{Christmas Day}
\holiday{\nextcalendaryear-01-01}{New Year's Day}


\end{tikzpicture}
\end{center}
\end{document}

If you compile it on you should get this result (screenshot).