In 1975, Kurt Klaus was entrusted with his first project. His task was to develop a calendar module for a pocket watch. The first prototypes followed. In 1977, the result was presented at the Basel watch fair, Reference 5500, a Lépine pocket watch with a calendar and moon phase display. Within its 18 kt gold case there was a 17 ligne gilded brass movement caliber 9721 with hand engraved bridges. Even at this time, Kurt Klaus had his own idea and deep desire: he wanted to create the “perpetual calendar” for the wrist.
The famous Il Destriero Scafusia (Ref. 1868), launched in 1993, is considered the 'warhorse from Schaffhausen'. In a movement with a diameter of just 35 mm, 750 individually manufactured and meticulously processed parts are at work. 76 jewels guarantee minimal friction and abrasion. 21 complex functions and displays are the result. The automatic wind-up was consciously omitted so that the exceptional beauty of the movement - protected by sapphire crystal - can be admired. All inscriptions and decorations on the case and movement are engraved by hand.
As the basic functional principles of the perpetual calendar have remained virtually unchanged since 1985, the mechanism itself can be found in a wide selection of current IWC timepieces that include further technical additions. For example, a digital display for the date and month can be found in the Aquatimer Perpetual Calendar Digital Date-Month Ed. “50 Years Aquatimer” (Ref. IW379403) and Ingenieur Perpetual Calendar Digital Date-Month (Ref. IW381701). Moreover, the further developed double-moon complication which allows for a view on the moon from both the northern and southern hemispheres are featured in the current models of the Portugieser Perpetual Calendar (Ref. IW503401 and IW503404).
Learn more about perpetual calendar watches made in Schaffhausen and discover the full collection.