Rolex watch

The Datejust owes its name to the date display window on the dial. Like the time, the date was traditionally indicated by a hand on the circumference of the dial. In 1945, this made the Datejust the first waterproof self-winding chronometer wristwatch to show the date in numbers with a window at 3 o’clock on the dial. Before becoming a watchmaking standard, this type of display was seen as a major breakthrough. It works by fitting the calibre with a 31-day disc and a mechanism allowing it to turn at midnight.