While you have until the day your reservation begins for a room only reservation.
We used to say at check-in but with the new online check-in process that starts as early as 60 days before your arrival, if you have a credit card already attached, your card will be charge on the day your resort stay begins. You also have the option to prepay all or part of the remaining room-only balance prior to your arrival.
If you check-in at the front desk, the CM will ask if you want to charge your room balance to your card on file or you can provide a different payment: cash, gift card or different credit card at this time.
Dave