The mechanically programmed perpetual calendar is the supreme achievement in the art of watchmaking. IWC’s perpetual calendar was originally designed in the early 1980s by ingenious watchmaker Kurt Klaus and has been continuously improved since then. It comprises 87 individual parts and will display the date, day, month, year in four digits and even the leap years for the next 577 years. All the displays are easily adjusted via the crown. Some models are supplied with an additional century slide, so the watch can continue showing the correct date until 2499. Other complications also run on the basis of the perpetual calendar, among them the perpetual moon phase display and the digital date display.