return if $params{config}->start_date > $params{end_date};
my $first_date = $params{config}->start_date->clone->set_year($self->year);
- my $net = $params{config}->order->netamount * (12 / $params{config}->get_period_length);
+ my $net = $params{config}->order->netamount * (12 / $params{config}->get_billing_period_length);
my $sord = $self->data->{sales_orders};
$sord->{months }->[ $first_date->month - 1 ] += $net;