business day
A business day is a duration of time standardized to the seven-day work week, used to differentiate calendar days, based on a seven-day week, from the time period when a company is in operation.

In the Western world, Saturdays and Sundays are not counted as business/working days. In some Muslim countries and in Israel, this applies to Friday and Saturday.

Business days are common measurements in companies with time-sensitive services, such as shipping or payment processing. As an example, when sending a package with a shipping company such as FedEx, a shipment dispatched on a Thursday that is to be delivered in "two business days" will arrive on the following Monday.

In the United States of America, a work day is generally referred to as a weekday, not including Saturday and Sunday.

-Wikipedia
I ordered these new Molotow markers from artprimo.com on Thursday, it said they'd arrive in 2-5 business days so I guess they'll arrive on Monday-Thursday.