Obviously you want to keep track of your Box items. In the "Next Shipment" overview you can see all items that are eligible to be included in your next Box shipment.
However, if for some reason you simply can't wait for your next Box Day, you can choose to have all available items shipped to you immediately. You'll find a nice big button to do so under the "Next shipment" section. Please take into consideration that a new Box Date will automatically be calculated if you use option. We do this to avoid situations where you might get multiple shipments very close to each other which would lead to unwanted additional shipping costs.