The Day-Date is Rolex's flagship watch and has been in production since 1956. It is the most expensive watch in Rolex's lineup, with prices starting at $12,000. The Day-Date is made from precious metals like gold and platinum, and its President bracelet is also made from these materials. The Day-Date's movements are all certified by COSC (Contrôle Officiel Suisse des Chronomètres), which is the highest standard of accuracy for watches. All of these factors contribute to the high price tag of the Day-Date.