The 15-Day Brent crude oil market is so-called because a seller must give a buyer a minimum 15 days notice of the intended loading dates for a cargo of Brent Blend North Sea crude oil in any particular month traded. 15-Day Brent is traded in discreet months. At the point where the buyer—who may be at the end of a long trading chain—is informed of the loading dates, the cargo becomes a so-called Dated Brent cargo.