public function getTimeOptions() {
    $options = [
      'all' => 'All'
    ];
    // Add options each half hour from 00:00:00 to 23:30:00 with values
    // 12:00:00 AM to 11:30:00 PM.
    $time = 18000;
    for ($i = 0; $i < 48; $i++) {
      $options[date('H:i:s', $time)] = date('g:i:s A', $time);
      $time += 1800;
    }
    return $options;
  }