Sometimes I plan flights around real life goings on (work, house work etc.), and plan my flights around what time I want to be landing.
Currently to do that, I have to create a flight, look at the duration, then subtract that duration from the arrival time I want and then generate a new flight with the departure time I have worked out.
It would be good if we could plan routes based on the arrival time, as well as the departure time. In my situation above it would also save a generated flight.