If a traveler asks for a date that falls after your booking cutoff (e.g. you require 48 hours' notice but they need to book for tomorrow), you'll need to temporarily adjust your cutoff setting before the booking can go through.
Go to My Profile → click on the Experience.
Go to the bottom of the page and click on Share and select the pencil icon to edit.
In Provide Experience Details, find the field Number of hours booking closes before start.
Lower it temporarily — for example: 12 hours to allow booking for the next day - or 4 hours to allow same-day booking.
Check your Booking Calendar to confirm the date/time now shows as available. If it doesn't, create a new Entry manually (see Adding a Single Entry above).
Let the traveler know they can book, and ask them to do so as soon as possible.
Once they've booked, reset the cutoff back to your normal value. If you forget, you may receive other last-minute bookings unexpectedly.