Connaître le jour en rapport avec une date

$ $ cal 03 2010
     March 2010     
Su Mo Tu We Th Fr Sa
    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         
                    
$ ./day 28/2/2010
dimanche
$ ./day 6/3/2010
samedi
$ ./day 04/7/1996
jeudi
$ ./day 30/11/2003
dimanche
$ ./day 04/9/2003
jeudi
$ ./day 6/6/1944
mardi
$ 
$ cat day
#!/bin/bash

set $(echo $1 | sed -e 's+/+ +g')
cal $2 $3 |nawk -v d=$1 'BEGIN{split("dimanche lundi mardi mercredi jeudi vendredi samedi",j)}
NR>2 {sub("^0","",d) ; for(n=1;n<8;n++)if(substr($0,1+((n-1)*3),2)+0 == d)exit} ; END{print j[n]}'
$ 

date +%A

date -d '2008/12/24' +'%A' 
mercredi

$ date=2010/3/5
$ perl -e 'use  Time::Piece ;my $t = Time::Piece->strptime($ARGV[0],"%Y/%m/%d");print $t->strftime("%u\n")' $date
5
$ 
$ date=2010/8/7
$ perl -e 'use  Time::Piece ;my $t = Time::Piece->strptime($ARGV[0],"%Y/%m/%d");print $t->strftime("%u\n")' $date
6
$ date=2008/12/24
$ perl -e 'use  Time::Piece ;my $t = Time::Piece->strptime($ARGV[0],"%Y/%m/%d");print $t->strftime("%u\n")' $date
3
$ 

$ date=28/2/2010
$ perl -e 'use  Time::Piece ;my $t = Time::Piece->strptime($ARGV[0],"%d/%m/%Y");print $t->strftime("%A\n")' $date
Sunday
$ 

$ cat date.c
#include <stdio.h>
#include <time.h>

main(int argc, char **argv)
{
	struct tm tm;
	char buf[128];

	strptime(argv[1],"%d/%m/%Y", &tm);
	strftime(buf, sizeof(buf), "%A", &tm);
	printf("%s\n", buf);
}
$ make date
cc     date.c   -o date
$ ./date 28/2/2010
Sunday
$