LaTeX: to make your document aware of Premium Friday

scpremiumfriday.sty

%%
%% This is file 'scpremiumfriday.sty'.
%% 
%% Copyright (c) 2017 Takayuki YATO (aka. "ZR")
%%   GitHub:   https://github.com/zr-tex8r
%%   Twitter:  @zr_tex8r
%%
%% This package is distributed under the MIT License.
%%

%% package declaration
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{scpremiumfriday}[2017/03/24 v0.2]
\def\sczpf@pkgname{scpremiumfriday}

%--------------------------------------- check premium-friday-ness

%% \ifsczpf@premium@friday
\newif\ifsczpf@premium@friday
\begingroup
  \def\sczpf@check@premium@friday@a{%
    \@tempcnta\year \multiply\@tempcnta1461 \divide\@tempcnta4
    \@tempcntb\year \divide\@tempcntb100 \advance\@tempcnta-\@tempcntb
    \divide\@tempcntb4 \advance\@tempcnta\@tempcntb
    \@tempcntb\month \advance\@tempcntb-2 \multiply\@tempcntb520
    \divide\@tempcntb17 \advance\@tempcnta\@tempcntb
    \advance\@tempcnta-678912 \advance\@tempcnta\day}
  \ifnum\month<3 \advance\month12 \advance\year-1 \fi
  \sczpf@check@premium@friday@a \count@\@tempcnta
  \advance\month1 \day1
  \ifnum\month>14 \month3 \advance\year1 \fi
  \sczpf@check@premium@friday@a \advance\@tempcnta-3
  \divide\@tempcnta7 \multiply\@tempcnta7 \advance\@tempcnta2
  \ifnum\@tempcnta=\count@ \aftergroup\sczpf@premium@fridaytrue \fi
\endgroup

%% if not the day, then quit right now
\ifsczpf@premium@friday\else
\expandafter\endinput\fi\relax

%% \ifsczpf@go@home
\newif\ifsczpf@go@home
\ifnum\time<900 \else
  \sczpf@go@hometrue
\fi

%--------------------------------------- prepare the hook

%% \sczpf@begindoc@hook
\let\sczpf@begindoc@hook\@empty
\begingroup
  \toks@\expandafter{\document}
  \xdef\document{%
    \endgroup
    \noexpand\sczpf@begindoc@hook
    \begingroup
    \the\toks@}
\endgroup

%--------------------------------------- premium console message

%% \sczpf@message@with
\begingroup
\catcode`\^^A=14 \catcode`\#=12
\catcode`\^^\=0 \catcode`\^^[=1 \catcode`\^^]=2 \catcode`\^^X=6
\endlinechar=10 \catcode10=12 \catcode96=7 \let\do\@makeother
\dospecials``\gdef``\sczpf@message@with``X1``X2``[``A
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
       ____
    ___HHHH   _____                  WOW!
   / .   . \ |NICE!|       It's Premium Friday today!
   \  ---  / |~~~~~
 V :#######: Y             ``X1
  \/   o*"*\/                                ``X2
  {    o    }
   \_______/                                         HURRAY!!
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%``]``A
``\endgroup%

%% \sczpf@message
\ifsczpf@go@home
  \def\sczpf@message{\sczpf@message@with
   {Now it's time to go home....}{}}%
\else
  \def\sczpf@message{\sczpf@message@with
   {How are you going to spend time}{after 3 p.m.?}}%
\fi

%--------------------------------------- premium output

%% variables
\newif\ifsczpf@scsnowman@ok

%% \sczpf@try@load@scsnowman
\def\sczpf@try@load@scsnowman{%
  \sczpf@scsnowman@oktrue
  \IfFileExists{scsnowman.sty}{}{\sczpf@scsnowman@okfalse}%
  \IfFileExists{tikz.sty}{}{\sczpf@scsnowman@okfalse}%
  \ifsczpf@scsnowman@ok
    \ifx\pgfsysdriver\@undefined
      \ifnum0%
          \ifx\XeTeXversion\@undefined\else1\fi
          \ifx\outputmode\@undefined\else \the\outputmode \fi
          \ifx\pdfoutput\@undefined\else \the\pdfoutput \fi >\z@
        \RequirePackage{graphicx}%
      \fi
      \ifcase0\csname sczpf@gd/%
          \ifx\Gin@driver\@undefined\else\Gin@driver\fi
          \endcsname\relax
      \or \edef\pgfsysdriver{pgfsys-\Gin@driver}%
      \else
        \IfFileExists{pgfsys-luatex.def}{%
          \def\pgfsysdriver{pgfsys-luatex.def}%
        }{\IfFileExists{luatex85.sty}{%
          \def\pgfsysdriver{pgfsys-pdftex.def}%
          \RequirePackage{luatex85}%
        }{}}%
      \fi
    \fi
    \ifx\pgfsysdriver\@undefined
      \sczpf@scsnowman@okfalse
    \else
      \RequirePackage{tikz}%
      \RequirePackage{scsnowman}%
    \fi
  \fi}
\@namedef{sczpf@gd/luatex.def}{2}
\@namedef{sczpf@gd/pdftex.def}{1}
\@namedef{sczpf@gd/xetex.def}{1}
\@namedef{sczpf@gd/dvips.def}{1}
\@namedef{sczpf@gd/dvipdfmx.def}{1}

%% \sczpf@prepare@output
\def\sczpf@prepare@output{%
  \DeclareFontFamily{OT1}{sczpfCmfi}{}%
  \DeclareFontShape{OT1}{sczpfCmfi}{m}{n}{<->cmfi10}{}%
  \sczpf@try@load@scsnowman
  \ifsczpf@scsnowman@ok
    \definecolor{sczpfBrown}{rgb}{0.4,0.1,0.0}%
    \definecolor{sczpfGreen}{rgb}{0.0,0.5,0.0}%
    \definecolor{sczpfRed}{rgb}{1.0,0.0,0.0}%
    \definecolor{sczpfSnow}{rgb}{0.6,0.8,1.0}%
    \def\sczpf@snowman{%
      \begingroup
        \usefont{T1}{lmr}{m}{n}\fontsize{38.4}{0}\selectfont
        \scsnowman[hat=sczpfGreen,muffler=sczpfRed,%
          arms=sczpfBrown,snow=sczpfSnow,scale=10]%
      \endgroup}%
  \else
    \def\sczpf@snowman{%
      \begingroup
        \font\x=ipxm-r-u26 at 300pt\relax \x
        \symbol{"03}%
      \endgroup}%
  \fi}

%% \sczpf@make@output
\def\sczpf@make@output{%
  \parindent\z@
  \usefont{OT1}{sczpfCmfi}{m}{n}\fontsize{72}{96}\selectfont
  \hbox to\hsize{\hskip1.5em Premium\hfil}%
  \hbox to\hsize{\hfil Friday!!\hskip1.5em}%
  \vskip 20pt
  \hbox to\hsize{\hfil\sczpf@snowman\hfil}%
  \vskip 20pt
  \usefont{OT1}{sczpfCmfi}{m}{n}\fontsize{48}{72}\selectfont
  \hbox to\hsize{\hfil Time to Go Home!\hfil}}

%--------------------------------------- the hook

%% register
\ifsczpf@go@home
  \g@addto@macro\sczpf@begindoc@hook{%
    \sczpf@prepare@output}
\fi
\g@addto@macro\sczpf@begindoc@hook{%
  \immediate\write\@unused{\sczpf@message}}
\ifsczpf@go@home
  \g@addto@macro\sczpf@begindoc@hook{%
    \output{\setbox\z@\box\@cclv \deadcycles\z@}%
    \shipout\vbox{%
      \moveleft1in\vbox{%
        \hsize=210mm \linewidth\hsize
        \kern-1in \kern40mm
        \sczpf@make@output}}%
    \nonstopmode\@@end}
\fi

%--------------------------------------- done
\endinput
%% EOF

test-scpremiumfriday.tex

% upLaTeX文書
\documentclass[uplatex,dvipdfmx,a4paper]{jsarticle}
\usepackage{scpremiumfriday}% プレミアムフライデー対応!!
\usepackage{color}
\title{幸せな{\LaTeX}者のための{\TeX}言語ガイド}
\author{某ZR}
\begin{document}
\maketitle

\section{いきなり結論}
{\TeX}言語危険、\textcolor{red}{\sffamily ダメゼッタイ！}

\end{document}