https://community.expensify.com/discussion/13760/how-to-change-date...
The United Airlines cancellation policy delivers its flyers with a 24 hour risk-free window, under which passengers can cancel their bookings for free and will be eligible for a complete refund, regardless of fare type. However, if you cancel your flight after 24 hours, then you have to pay a certain amount as a United Airlines cancel flight fee.