use DateTime;
use strict;
use warnings;
my $str = "2004-01-14";

my( $y, $m, $d ) = split /\D/,$str;

my $delta = DateTime->new(
    year => $y,
    month => $m,
    day => $d,
)->delta_days(
    DateTime->now(),
);

die $delta->days;

__END__
0 at datetime4.pl line 16.