If you pay at the bank or via bank transfer before 4pm, your account balance and available credit should update the next working day. If you make your payment after 4pm, they should update within two working days.
The date you send your payment is the date it will be applied to your account, once it has cleared. If your payment is still clearing when your due date passes, you won’t be charged a late payment fee, as long as the payment was sent before the due date.