#! perl -slw
use strict;
use GD::Graph::bars;

my @d1 = (
    [ "2010/03/29 14:00:00", "2010/03/29 14:00:00" ],
    [ 13, 15 ],
    [ 20, 21 ],
    [ 4, 9 ],
);

my $graph = GD::Graph::bars->new(1000, 800);

open PNG, '>:raw', "$0.png" or die $!;
print PNG $graph->plot( \@d1 )->png;
close PNG;
system "$0.png";