Here are few of the best possible ways to change your flight date without having to pay an extra fee:
Having a non-refundable ticket? Don’t worry it can be changed too! As long as you have booked your ticket seven days in advance of your flight, you can change or cancel it within 24 hours of booking without paying a cancellation fee.
Try making same day changes rather than changing the departure date. It is much easier and cheaper to reschedule your flight time rather than you flight date. Few airlines charge a minimal fee of only $50 to change you flight timings.
Always try and buy refundable tickets or flexible tickets. They are a little expensive but it is way better than wasting all your money on tickets that cannot be changed.
Some airlines, like JetBlue, base their change fees on the cost of the ticket, so the less you spend on the individual ticket the less you'll be charged in change fees. So, buy cheaper tickets!