PHP: Calculating Monthly/Yearly Billing Dates - Same day next month

I've been looking for a way to accurately calculate the next/future billing date in a way that a month will not be skipped. For example for Jun 31 I want the next billing date to be Feb 28 (or 29 when applicable). I found this great solution. Here is an update of that code to support more than 1 month in the future. Hope that helps.

Code:

function calculateBillingDate($startDate, $numberOfCycles = 1) {

    $currentMonth = date('n', $startDate);
    $nextMonth = (($currentMonth + $numberOfCycles) % 12);
    if ($nextMonth === 0) {
        $nextMonth = 12;
    }

    $targetDate = new \DateTime();
    $targetDate->setTimestamp($startDate);

    $targetDate->add(new \DateInterval('P' . $numberOfCycles . 'M'));
    while ((int)$targetDate->format('m') !== $nextMonth) {
        $targetDate->sub(new \DateInterval('P1D'));
    }

    return $targetDate;

}