looks like a nice project. If I can have one suggestion:
offer the option to enter a fixed date for one of the destinations (instead of the start date ).
Use case: If I am flying for a business trip to a given destination, the dates are pretty much set there. There is another place close by that I would like to visit and I don't care too much if it will be before or after the business trip, but the business trip needs to happen on selected dates.