summaryrefslogtreecommitdiff
path: root/macros/latex/contrib/eukdate/eukdate.dtx
blob: bcee0cf05c68e58987d5c65799c06cd720d1382b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
% \iffalse meta-comment
%
% Copyright Andrew Gilbert Moschou 2008
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3c
% of this license or (at your option) any later version.
% The latest version of this license is in
%
%   http://www.latex-project.org/lppl.txt
%
% and version 1.3c or later is part of all distributions of LaTeX
% version 2005/12/01 or later.
%
% \fi
%
% \iffalse
%<package>\NeedsTeXFormat{LaTeX2e}
%<package>\ProvidesPackage{eukdate}[2009/03/18 v1.04 UK format date (Hart's Rules) with weekday]
%
%<*driver>
\documentclass{ltxdoc}
\usepackage{eukdate}
\EnableCrossrefs
\CodelineIndex
\newcommand\US{\textsc{us}}
\newcommand\UK{\textsc{uk}}
\newcommand\floor[1]{\left\lfloor#1\right\rfloor}
\newcommand\pp[1]{\left(#1\right)}
\usepackage{amsmath}
\hyphenation{ori-gin-al-ly ca-len-dar}
\frenchspacing
\begin{document}
  \DocInput{eukdate.dtx}
\end{document}
%</driver>
% \fi
%
% \CheckSum{163}
%
% \GetFileInfo{eukdate.sty}
%
% \DoNotIndex{\addtocounter}
% \DoNotIndex{\day,\DeclareOption,\def,\divide}
% \DoNotIndex{\edef,\else,\eukordinal,\ExecuteOptions}
% \DoNotIndex{\fi}
% \DoNotIndex{\ifcase,\ifnum}
% \DoNotIndex{\loop}
% \DoNotIndex{\month,\multiply}
% \DoNotIndex{\newcommand,\newcounter,\newif,\number}
% \DoNotIndex{\or}
% \DoNotIndex{\ProcessOptions}
% \DoNotIndex{\relax,\repeat}
% \DoNotIndex{\setcounter,\space}
% \DoNotIndex{\year}
%
% \title{The \textsf{eukdate} package}
% \author{Andrew Gilbert Moschou\\\textsf{andmos@gmail.com}}
% \makeatletter
% \date{\today\\v.~\expandafter\@gobble\fileversion}
% \makeatother
%
% \maketitle
%
% \section{Introduction}
%
% This package redefines \DescribeMacro{\today}|\today|, to typeset |\today|'s date in, the format \emph{Day, Date Month Year} (here, called `\UK\ format'), e.g., `\weekday, \number\day\ \monthname\ \number\year', as is preferred in many parts of the world outside the \US. Thus, |\maketitle| uses the \UK\ format (instead of the default \US\ format, e.g. \monthname\ \number\day, \number\year, as used in the |article| class).
%
% From \emph{Hart's Rules} (Hart, H., 1983. \emph{Hart's Rules for Compositors and Readers at the University Press Oxford}, Thirty-ninth edition, Completely revised, Originally compiled by Horace Hart, \textsc{m.a.}, Printer to the University, 1883--1915, Oxford University Press, Oxford, pp.~18--19.):
% 
% \makeatletter\begin{center}\begin{minipage}[t]{100mm}
% \def\thempfootnote{{\@arabic\c@mpfootnote}}
% In dates, print 25 June 1978.\footnote{~This will not apply to quotations, nor to reprints of documents. As to the form May 19, 1862, Sir James Murray said, `This is not logical: 19 May 1862 is. \emph{Begin} at day, \emph{ascend} to month, \emph{ascend} to year; not \emph{begin} at month, \emph{descend} to day, then \emph{ascend} to year.'} Omit comma between month and year: `The delay after November 1967 was due to an oversight.'
% \end{minipage}\end{center}\makeatother
%
% This package also determines |\today|'s day of the week, which still makes the package useful even to Americans who might use the |usdate| option. The day of the week is calculated according to Zeller's congruence:
% \begin{align*}w &= \begin{cases}
% d + \floor{\frac{26}{10}\pp{m+1}} + y + \floor{\frac{y}{4}} + \floor{\frac{c}{4}} - 2c\pmod 7 & \mbox{Gregorian calendar}\\
% d + \floor{\frac{26}{10}\pp{m+1}} + y + \floor{\frac{y}{4}} + 5 - c\pmod 7 & \mbox{Julian calendar}
% \end{cases}\end{align*}where $d$ is the day of the month, $m$ is the number of the month, $y$ is the two digit year, $c$ is the century (so the four digit year is given by $100c+y$) and $w$ represents the day of the week (0 for Saturday through to 6 for Friday); January and February are counted as months 13 and 14 of the previous year.
%
% \makeatletter
% The ordinal indicator of the date (in e.g. \number\day\textsuperscript{\euk@ordinal}, \number\day\euk@ordinal) is absent because its use is outdated.
% \makeatother
%
% \section{Usage}
%
% The package is invoked with |\usepackage{eukdate}|. This package also defines \DescribeMacro{\weekday}|\weekday| to typeset |\today|'s day of the week and \DescribeMacro{\monthname}|\monthname| to typeset the name of |\today|'s month (`\weekday' and `\monthname' when this document was typeset).
%
% \subsection{Options}
%
% \begin{description}
% \item[\sffamily no-weekday]Suppresses the weekday when typesetting |\today|, for example, `\number\day\ \monthname\ \number\year'. |\weekday| is still defined and can be used in the document.
% \item[\sffamily  ukdate]Typesets |\today| in \UK\ format, `\weekday, \number\day\ \monthname\ \number\year'. This option is applied by default, if the |usdate| option is not specified.
% \item[\sffamily  usdate]Typesets |\today| in \US\ format, `\weekday, \monthname\ \number\day, \number\year'.
% \item[\sffamily  gregorian]Calculates the day of the week according to the Gregorian calendar, which is the calendar that is generally used today. This option is applied by default, if the |julian| option is not specified.
% \item[\sffamily  julian]Calculates the day of the week according to the Julian calendar. However, since |\today|'s date is not \emph{today}'s date, as intepreted using the Julian calendar, this option is of limited use and can be safely ignored for every day use.
% \end{description}
%
% \section{Why a new solution?}
%
% It is natural to ask `Why a new solution to this problem?' because surely, somebody has already dealt with the issue. This is true but other solutions tend to be cumbersome. A similar effect can be achieved with |\usepackage[australian]{babel}| or |\usepackage[english,cleanlook]{isodate}|, but these instances do not include the day of the week. The day of the week can be calculated separately with scripts like |dow| or |dayofweek|, but neither is automatically integrated into the definition of |\today|. The |datetime| package can do this with the |\longdate| command, but there are minor format issues, which can be fixed only by defining a new format.
%
% This package was created to offer a simple method to set the date using a format according to \emph{my} preferences in a way that is portable to each system. It supports only a handful of date formats and in no way aims to be comprehensive.
%
% \StopEventually{\PrintIndex}
% \section{\textsf{eukdate.sty}}
%    \begin{macrocode}
\newif\if@euk@noweekday
\newif\if@euk@usdate
\newif\if@euk@julian
\DeclareOption{no-weekday}{\@euk@noweekdaytrue}
\DeclareOption{ukdate}{\@euk@usdatefalse}
\DeclareOption{usdate}{\@euk@usdatetrue}
\DeclareOption{gregorian}{\@euk@julianfalse}
\DeclareOption{julian}{\@euk@juliantrue}
\ExecuteOptions{ukdate,gregorian}
\ProcessOptions\relax
%    \end{macrocode}
% \subsection{Zeller's congruence}
% Actually, the equivalent congruence:\begin{align*}w &= \begin{cases}
% d + \floor{\frac{26}{10}\pp{m+1}} + y + \floor{\frac{y}{4}} + \floor{\frac{c}{4}} + 5c\pmod 7 & \mbox{Gregorian calendar}\\
% d + \floor{\frac{26}{10}\pp{m+1}} + y + \floor{\frac{y}{4}} + 5 + 6c\pmod 7 & \mbox{Julian calendar}
% \end{cases}\end{align*}is used instead of Zeller's, as claimed, to simplify the algorithm for the modulo operation.
%    \begin{macrocode}
\newcounter{euk@date}
\newcounter{euk@month}
\newcounter{euk@century}
\newcounter{euk@year}
\setcounter{euk@date}{\number\day}
\setcounter{euk@month}{\number\month}
\setcounter{euk@century}{\number\year}
\divide\c@euk@century by 100
\setcounter{euk@year}{\number\year}
\addtocounter{euk@year}{-\theeuk@century00}
\ifnum\number\theeuk@month<3
  \addtocounter{euk@month}{13}
  \addtocounter{euk@year}{-1}
\else
  \addtocounter{euk@month}{1}
\fi
\multiply\c@euk@month by 26
\divide\c@euk@month by 10
\addtocounter{euk@date}{\theeuk@month}
\addtocounter{euk@date}{\theeuk@year}
\divide\c@euk@year by 4
\addtocounter{euk@date}{\theeuk@year}
\if@euk@julian
  \addtocounter{euk@date}{6\theeuk@century}
  \addtocounter{euk@date}{5}
\else
  \addtocounter{euk@date}{5\theeuk@century}
  \divide\c@euk@century by 4
  \addtocounter{euk@date}{\theeuk@century}
\fi
%    \end{macrocode}
% The modulo operation.
%    \begin{macrocode}
\loop\ifnum6<\theeuk@date
  \addtocounter{euk@date}{-7}
\repeat
%    \end{macrocode}
% \subsection{Definitions}
% \begin{macro}{\weekday}
% Define |\weekday| to typeset the day of the week.
%    \begin{macrocode}
\newcommand\weekday{%
  \ifcase\theeuk@date Saturday\or Sunday\or Monday\or
    Tuesday\or Wednesday\or Thursday\or Friday\fi}
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\monthname}
% Define |\monthname| to typeset the month.
%    \begin{macrocode}
\newcommand\monthname{%
  \ifcase\number\month\or January\or February\or March\or
    April\or May\or June\or July\or August\or
    September\or October\or November\or December\fi}
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\today}
% Redefine |\today|.
%    \begin{macrocode}
\def\today{%
  \if@euk@noweekday\else\weekday,\space\fi
  \if@euk@usdate
    \monthname\space\number\day,%
  \else
    \number\day\space\monthname
  \fi
  \space\number\year}
%    \end{macrocode}
% \end{macro}
% An `undocumented' feature.
%    \begin{macrocode}
\edef\euk@ordinal{%
   \ifcase\number\day\or st\or nd\or rd\or th\or th\or
     th\or th\or th\or th\or th\or th\or th\or th\or th\or
     th\or th\or th\or th\or th\or th\or st\or nd\or rd\or
     th\or th\or th\or th\or th\or th\or th\or st\fi}
%    \end{macrocode}
% \Finale
\endinput