Buffer displays the plan's Buffer Days to Charge Before Renewal: "-N days" means the charge may be attempted up to N days before the renewal date, "On Day" means it is charged on the renewal date itself. It is read-only here; edit it on the plan under Kitchen Settings > Weekly Subscription (plans). With a buffer, the subscription shows a Next Billing Period range and the renewal is attempted on the first scheduled run inside that range, which gives a few days to retry if the card fails before the customer's dates run out.