public function isApplicable(Enquiry $enquiry) : bool
 {
     if ($enquiry->isReturn()) {
         $arrivalUnix = strtotime($enquiry->getInboundDate());
         $departureUnix = strtotime($enquiry->getOutboundDate());
         return $departureUnix - $arrivalUnix >= $this->minStay * 84600;
     }
     return false;
 }
 public function isApplicable(Enquiry $enquiry) : bool
 {
     return strtotime($enquiry->getInboundDate()) - time() >= $this->prebookDays * 86400;
 }