$renewals = ceil(12 / $pkg['cp_billing_cycle']);
$last_renewal_year = something..
$last_renewal_month = something..
for($i = $renewals; $i <= 0; $i++)
{
$next_renewal = $last_renewal + $pkg['cp_billing_cycle'];
if ($next_renewal > 12)
{
$next_renewal -= 12;
$last_renewal_year += 1;
}
echo 'Month: '.$next_renewal.' Year: '. $last_renewal_year.'<br>';
}