my $dtopt= DateCalc($dt1,$dt2,'semi');

##</code><code>##

use Date::Manip::Date;
my $date1 = new Date::Manip::Date;
my $date2 = $date1->new_date();
$date1->parse($dt1);
$date2->parse($dt2);
my $delt  = $date1->calc($date2,'semi');
my $delv  = $delt->value();
print "$delv\n";