In shipping, a business day refers to the days when the courier company operates for the chosen shipping method. It is important to note that weekends and public holidays are typically not considered business days. The length of a business day can vary depending on the carrier, destination, method, and timing of the shipment. For example, the business day for USPS is from Monday to Saturday, while the business day for FedEx and UPS is from Monday to Friday. If a courier ships a parcel on a Thursday that will be delivered in "two business days", it will arrive on the following Monday if neither Friday nor Monday are holidays.