$array = array();
$today = date("Y-m-d"); // get today's date

foreach($arrayOfObjs as $obj){
    if ($obj->get("renewalDate") >= $today){
        array_push($array, $obj->get("renewalDate"));
    }else{
        switch($obj->get("recurrencePeriod")){
            case 1:
       /*
       * All cases follow same structure
       * Build the date in format Y-m-d from renewalDate out of the obj.
       * Loop through the date while it's less than today.
       * After date is greater than today return date add to array
       */

       $date = DateTime::createFromFormat("Y-m-d", $obj->get('renewalDate'));
       while($date <= $today){
          $date->add(new DateInterval('P7D'));
        }
        $diff = date_diff($today, $date);
        if($diff->format('%a') <= 7){
          $obj->renewalDate($date);
          array_push($array, $obj);
        }
        break;