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"
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"
[{'booking_start_date': '2016-09-26 17:13:49'}, {'booking_start_date': '2016-04-01 06:28:08'}, {'booking_start_date': '2016-08-04 10:33:00'}, {'booking_start_date': '2016-07-25 02:57:04'}, {'booking_start_date': '2017-03-04 02:23:49'}, {'booking_start_date': '2016-06-07 05:05:18'}, {'booking_start_date': '2016-09-28 05:00:50'}]