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%% Advance Date Package for LaTeX2e %%
%% (C) Z. Wagner -- Ice Bear Soft, 20 Oct 1996, <wagner@mbox.cesnet.cz> %%
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%% Copyright 1996 Zdenek Wagner %%
%% %%
%% This work may be distributed and/or modified under the %%
%% conditions of the LaTeX Project Public License, either version 1.3 %%
%% 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 1.3 or later is part of all distributions of LaTeX %%
%% version 2005/12/01 or later. %%
%% %%
%% This work has the LPPL maintenance status `maintained'. %%
%% %%
%% The Current Maintainer of this work is Zdenek Wagner. %%
%% %%
%% This work consists of all files listed in manifest.txt. %%
%% %%
%% This licence information was added 2010/11/22 by %%
%% Clea F. Rees with the permission of Zdenek Wagner. %%
%% %%
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%% This package contains macros which can add specified number of days %%
%% to the current date (as specified in \today) and print it. Some other %%
%% macros are also provided. It is intended for use e.g. in invoices %%
%% payable within 14 days from today etc. %%
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%% Macros with one default argument [in square brackets] %%
%% \AdvanceDate Default: [1] %%
%% Advances date the specified number of days and sets the result %%
%% to \today %%
%% \DayAfter Default: [1] %%
%% Advances date by call to \AdvanceDate, prints \today and restores %%
%% the oroginal value of \today %%
%% \SaveDate Default: [\s@v@dT@d@y] %%
%% Saves \today into the specified macro %%
%% \SetDate Default: [\s@v@dT@d@y] %%
%% Sets the date stored in \today. The argument must be in form: %%
%% [dd/mm/yyyy] and may be present in a macro because the argument %%
%% is always expanded before use. The value saved by \SaveDate can %%
%% be used here. %%
%% %%
%% Macros with one mandatory argument %%
%% \ThisDay sets \day %%
%% \ThisMonth sets \month %%
%% \ThisYear sets \year %%
%% \AdvMonth advances \month and fixes it %%
%% \AdvYear advances \year %%
%% %%
%% Macros without arguments %%
%% \FixMonth fixes \today so that 0 < \month < 13 %%
%% \FixDate fixes \today so that it is valid %%
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\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{advdate}[1996/10/20 Advance Date Package]
% KH code
\newcount\r@k \newcount\un@r
\newcount\m@l \m@l31
\newcount\m@s \m@s30
\newcount\M@s
\newcommand\is@LeapYear[1][\year]{\r@k#1\un@r\r@k
\divide\r@k4\multiply\r@k4\advance\r@k-\un@r
\ifnum\r@k=0%
\divide\un@r100\r@k\un@r\multiply\un@r100\advance\un@r-#1%
\ifnum\un@r=0%
\un@r\r@k \divide\un@r4\multiply\un@r4\advance\un@r-\r@k
\un@r\ifnum\un@r=0 29\else 28\fi
\else
\un@r 29%
\fi
\else
\un@r 28%
\fi
\r@k 337\advance\r@k\un@r}
\newcommand\m@sic{\ifcase \month \or \m@l \or \un@r \or \m@l \or \m@s \or \m@l \or \m@s
\or \m@l \or \m@l \or \m@s \or \m@l \or \m@s \or \m@l \fi}
\newcommand\FixMonth{%
\L@@p \ifnum\month<1 \advance\year\m@ne \advance\month12 \is@LeapYear \repeat
\L@@p \ifnum\month>12 \advance\year\@ne \advance\month-12 \is@LeapYear \repeat}
\newcommand\FixDate{%
\FixMonth \is@LeapYear
\l@@p \ifnum\day<1 \Pr@vD@y \repeat
\l@@p \M@s\m@sic \ifnum\day>\M@s \N@xtD@y \repeat
}
% We need a nested \loop and the user might call the macros from his/her \loop
\def\L@@p#1\repeat{\def\It@r@te{#1\relax \expandafter\It@r@te\fi}\It@r@te
\let\It@r@te\relax}
\def\l@@p#1\repeat{\def\it@r@te{#1\relax \expandafter\it@r@te\fi}\it@r@te
\let\it@r@te\relax}
\def\Pr@vD@y{%
\ifnum\day<-366
\ifnum\month>2
\advance\day\r@k \advance\year\m@ne \is@LeapYear
\else
\advance\year\m@ne \is@LeapYear \advance\day\r@k
\fi
\else
\advance\month\m@ne \FixMonth
\advance\day\m@sic
\fi}
\def\N@xtD@y{%
\ifnum\day>366
\ifnum\month>2
\advance\year\@ne \is@LeapYear \advance\day-\r@k
\else
\advance\day-\r@k \advance\year\@ne \is@LeapYear
\fi
\else
\advance\day-\M@s \advance\month\@ne \FixMonth
\fi}
\newcommand\AdvanceDate[1][\@ne]{\advance\day#1 \FixDate}
\newcommand\DayAfter[1][\@ne]{{\AdvanceDate[#1]\today}}
\newcommand\SaveDate[1][\s@v@dT@d@y]{%
\expandafter \expandafter \expandafter \expandafter
\expandafter \expandafter \expandafter \edef
\expandafter \expandafter \expandafter \expandafter
\expandafter \expandafter \expandafter #1\expandafter
\expandafter \expandafter \expandafter
\expandafter \expandafter \expandafter
{\expandafter \expandafter \expandafter \number
\expandafter \expandafter \expandafter \day
\expandafter \expandafter \expandafter /\expandafter \number
\expandafter \month \expandafter /\number \year}}
\newcommand\SetDate[1][\s@v@dT@d@y]{\edef\d@t@{#1}%
\expandafter\t@d@y\d@t@\t@d@y\FixDate}
\def\t@d@y#1/#2/#3\t@d@y{\day#1 \month#2 \year#3 \relax}
\newcommand\ThisDay[1]{\day#1 \relax}
\newcommand\ThisMonth[1]{\month#1 \relax}
\newcommand\ThisYear[1]{\year#1 \relax}
\newcommand\AdvMonth[1]{\advance\month#1 \FixMonth}
\newcommand\AdvYear[1]{\advance\year#1 \relax}