code: public function daysFromInstallation()
      {
          $stat = $this->statisticRepository->getStatByAction(self::FASTLY_INSTALLED_FLAG);
  
          if (!$stat->getCreatedAt()) {
              return null;
          }
          $installDate = date_create($stat->getCreatedAt());
          $currentDate = date_create($this->dateTime->gmtDate());
  
          $dateDiff = date_diff($installDate, $currentDate);
  
          return $dateDiff->days;
      }
docs: Calculates number of days since Fastly module installation
  
  @return mixed|null