It doesn't really matter how soon (or not) the booking is, a cancellation is a cancellation, @Priscilla165. If you have extenuating circumstances, try speaking to Airbnb customer services.
@Priscilla165 the cancellation fee is not important, much more important is the notice you'll get on your listing saying the host cancelled this booking. This can and will put guests off booking your place.
I suggest you find a way to host the guests.
Unless you have an extenuating circumstance and can cancel penalty free