IWC, Portugieser, Perpetual Calender, "Double Moon", ca 2018.

Kurt Klaus is a renowned master watchmaker who worked for IWC Schaffhausen for over four decades, during which he designed some of the most innovative and complicated perpetual calendar movements ever created. Klaus joined IWC in 1957 and soon established himself as a visionary watchmaker. He was particularly interested in the perpetual calendar complication, which he believed had the potential to revolutionize the watch industry.

One of Klaus's most significant contributions to watchmaking was the creation of the IWC perpetual calendar movement, which debuted in 1985. The movement was designed to be user-friendly and intuitive, with a unique "mechanical memory" that allowed it to automatically adjust for leap years. Klaus's perpetual calendar design was groundbreaking in that it required significantly fewer components than previous perpetual calendar mechanisms, making it more reliable, easier to manufacture, and more affordable.

The IWC perpetual calendar has since become a hallmark of the brand, and Klaus's work on the movement is widely regarded as a masterpiece of watchmaking. Klaus continued to refine and improve the perpetual calendar movement throughout his career at IWC, and his legacy lives on in the brand's current collection of perpetual calendar watches.

In conclusion, Kurt Klaus's work on the IWC perpetual calendar movement is a testament to his skill, ingenuity, and passion for watchmaking. His innovative design and commitment to precision have made IWC's perpetual calendar watches some of the most sought-after timepieces in the world, and his legacy continues to inspire and influence the watch industry today.