Most reservations offer a flexible cancellation policy. In this case, your reservation can be canceled up to 48-hours before check-in without penalty. Cancellations or modifications after this time will be charged the full amount including tax. If you decide to change the dates of your stay, the cancellation policy for the original booking will still apply. From there, you are welcome to make a new booking for any available dates.
Some reservations offer an additional discount for the benefit of a non-refundable rate. In this case, all reservations are final and cannot be moved or modified.