Return the booking start date and end date for the apartments that have type code "Duplex".
SELECT T1.booking_start_date ,  T1.booking_start_date FROM Apartment_Bookings AS T1 JOIN Apartments AS T2 ON T1.apt_id  =  T2.apt_id WHERE T2.apt_type_code  =  "Duplex"
"Dubleks" türü olan daireler için rezervasyon başlangıç ​​tarihi ve bitiş tarihini döndürün.