my $datetime  = $dt_obj->strftime("%a, %d %b %Y %T EST");

##</code><code>##

use DateTime::Format::Strptime;
my $formatter = DateTime::Format::Strptime->new(pattern => "%F  %T",time_zone=>'EST');
my $dt_obj    = $formatter->parse_datetime("2008-11-03  19:03:44");
print $dt_obj->strftime("%a, %d %b %Y %T %Z"), "\n";
# to convert to a different zone:
$dt_obj->set_time_zone('America/Chicago');
print $dt_obj->strftime("%a, %d %b %Y %T %Z"), "\n";

__END__

Mon, 03 Nov 2008 19:03:44 EST
Mon, 03 Nov 2008 18:03:44 CST