The Rolex Oyster Perpetual Day-Date is a COSC certified, self-winding chronometer manufactured by Rolex. Initially presented in 1956, the Day-Date was the first watch of its kind to display the date as well as the day, spelled in full. The calendar display is offered in 26 languages.
The Day-Date is one of Rolex's models made only in solid 18k yellow gold, 18k white gold, 18k Everose gold (Rolex's version of 18k rose gold), and platinum (PT950).
As of 2020, Rolex offers two sizes of the Rolex Day-Date: 40 mm and 36 mm.