mult1mate\crontab\TaskRunner::getRunDates PHP Method

    public static function getRunDates($time, $count = 10)
    {
        try {
            $cron = CronExpression::factory($time);
            $dates = $cron->getMultipleRunDates($count);
        } catch (\Exception $e) {
            return array();
        }
        return $dates;
    }

 public function getDates()
 {
     $time = $_POST['time'];
     $dates = TaskRunner::getRunDates($time);
     if (empty($dates)) {
         echo 'Invalid expression';
         return;
     }
     echo '<ul>';
     foreach ($dates as $d) {
         /**
          * @var \DateTime $d
          */
         echo '<li>' . $d->format('Y-m-d H:i:s') . '</li>';
     }
     echo '</ul>';
 }