If you’ve ever found yourself waiting at the airport all day, waiting for your international flight to leave, you may have wondered why they never take off in the morning. One reason for this is that it allows for more efficient use of the aircraft. By departing in the evening, the aircraft can complete a transatlantic flight overnight and then be used for additional flights during the day. Departing in the evening allows passengers to sleep during the flight and arrive at their destination in the morning feeling more refreshed, and it's easier to conduct hotel, car rental, or other business then. Leaving in the evening also allows airlines to take advantage of air flow patterns and time zones to save on fuel costs. Finally, many airports observe night curfew, meaning no take-offs or landing between 11 p.m. and 5 a.m.
