summaryrefslogtreecommitdiff
path: root/info/examples/tip/prevday.tip
blob: 2e4c8829be87961d7dc499f89778fec0b36135fe (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
% This macro source file is from the four volume series
% "TeX in Practice" by Stephan von Bechtolsheim, published
% 1993 by Springer-Verlag, New York.
% Copyright 1993 Stephan von Bechtolsheim.
% No warranty or liability is assumed.
% This macro may be copied freely if no fees other than
% media cost or shipping charges are charged and as long
% as this copyright and the following source code itself
% is not changed. Please see the series for further information.
%
% Version: 1.0
% Date: May 1, 1993
%
%
% This source code is documented in 26.12, p. III-374.
% Original source in file "macros6.TEX", starting line 773.
\wlog{L: "prevday.tip" ["macros6.TEX," l. 773, p. III-374]}%
% This file DOES belong to format "texip."
\InputD{legdate.tip}
\InputD{ndaysmo.tip}
\InputD{copydate.tip}
\catcode`\@ = 11
\newcount\@TempPrevDay
\def\PrevDay #1#2#3#4#5#6{%
    \CheckDate{#1}{#2}{#3}%
    \CopyDate{#1}{#2}{#3}{#4}{#5}{#6}%
    \advance #6 by -1
    \ifnum #6 = 0
        \advance #5 by -1
        \ifnum #5 = 0
            #5 = 12
            \advance #4 by -1
        \fi
        \NumberOfDaysInMonth{#4}{#5}{#6}%
    \fi
}
\catcode`\@ = 12