Advance Cancellations and Schedule Changes
If the airline cancels your flight in advance or changes its schedule more than a couple of hours, you can request either a refund or rebooking on another acceptable flight. Airlines don't guarantee their schedules; changes happen.
An airline is required to offer you a refund on your ticket (unused portion) if you don't want to travel at a later time, or pay for your accommodations if you are stranded somewhere because of a problem caused by the airline. You should expect a hotel room, paid for by the airline, and vouchers for food. Negotiate other incidental costs with the airline such as toiletries. The airline is expected to rebook you on the next available flight.
Change of Plans
If you change plans, most U.S. airlines have committed either to allow customers to hold a reservation for twenty-four hours or to provide refunds if customers cancel within twenty-four hours. Each airline abides by one or the other. Then, you pay penalties for changing plans with nonrefundable tickets, plus any fare difference.
You have some rights under U.S. credit card laws. When a refund is due, the airline must
forward a credit to your credit card company within seven business days after receiving a complete refund application. If the airline goes out of business before you fly, you'll be eligible for a refund from your card company in most cases.
If flights get canceled shortly before departure, your rights hinge on whether the problem was the airline's fault (mechanical breakdown or a crew scheduling problem) or whether the cancellation resulted from weather or circumstances beyond an airline's control.
For problems outside the airline's control, you are on your own. The airline is required only to rebook you on the next available flight. Some offer discounted rates at hotels. Some airports provide cots and blankets during major flight disruptions.
In the U.S., there are no federal requirements for compensation for delayed flights. Airline ticketing contracts promise to provide a seat on the next available flight.
(Source: Scott McCartney: The Wall Street Journal Guide to Power Travel)