Launched in 2012, the Oyster Perpetual Sky-Dweller features a dual time zone and an annual calendar. Known as Saros, the calendar is driven by a patented mechanism called the Ring Command and displays the month by means of 12 apertures around the circumference of the dial – the current month is shown in a contrasting colour. A compelling blend of technical sophistication and ease of use, the Sky-Dweller is the result of Rolex’s unique culture of innovation.