#!/usr/bin/perl
use Data::Dumper;
use strict;
#use re 'debug';

my  $foo_year = "2004-11-12 12:40:42";

test($foo_year);
test($foo_year);
test($foo_year);

sub test {
  my ($date) = @_;
  print $date,"\n";
  my ($year,$month,$day);
  $date =~ m/
    (\d+)  (?{ $year  = $^N })
    -
    (\d+)  (?{ $month = $^N })
    -
    (\d+)  (?{ $day   = $^N })
  /x;
  print "$year-$month-$day\n";
}