protected function getIntervalDefaultArray(\Club\BookingBundle\Entity\Field $field, $day)
 {
     $r = json_decode($field->getFieldLayout());
     $r = isset($r->{$day}) ? $r->{$day} : false;
     $open = new \DateTime();
     if (!isset($r->open)) {
         $open->setTime(8, 0, 0);
     } else {
         $n = preg_split("/:/", $r->open);
         $open->setTime($n[0], $n[1], 0);
     }
     $close = new \DateTime();
     if (!isset($r->close)) {
         $close->setTime(20, 0, 0);
     } else {
         $n = preg_split("/:/", $r->close);
         $close->setTime($n[0], $n[1], 0);
     }
     if (!isset($r->interval)) {
         $interval = new \DateInterval('PT60M');
         $range = new \DatePeriod($open, $interval, $close);
         $available = '';
         foreach ($range as $dt) {
             $work = clone $dt;
             $available .= $work->format('H:i') . '-';
             $work->modify('+' . $interval->i . ' minute');
             $available .= $work->format('H:i') . "\n";
         }
     } else {
         $interval = new \DateInterval('PT' . $r->interval . 'M');
         $available = $r->available_timeslots;
     }
     return array('open' => $open->format('H:i'), 'close' => $close->format('H:i'), 'interval' => $interval->i, 'available_timeslots' => $available);
 }