The Journey of Creating a Perpetual Calendar for a Wristwatch
Kurt Klaus translated the Gregorian calendar, with all its irregularities, into a mechanical system for a wristwatch during his time as head watchmaker at IWC Schaffhausen. The mechanism would continue running perfectly until 2499 with no corrections whatsoever. This legendary design was first featured in the Da Vinci Chronograph Perpetual Calendar released in the year 1985, which to this day, is still regarded as a massive milestone for watchmaking.
With its many nitty-gritties, the Gregorian calendar is a hurdle for anyone who would try to put it inside a watch. When we were little, a well-known method of counting the length of the months involved counting on your knuckles. However, simply knowing that months last 28, 30 or 31 days is not enough. We need to add a “leap” day, the 29th of February, every four years.
The 1970s was a time when the Swiss watchmaking industry was amidst its most testing crisis ever. Timepieces powered by a quartz crystal were being mass-manufactured in Japan. The problem was that the collective expertise of mechanical horologists all over the world was suddenly rendered superfluous.
Kurt Klaus, however, had other ideas. While many of his peers wailed in unison about the circumstances, Klaus got down to work. Around the mid-1970s, he produced the first calendar for a magnificent open-face pocket watch and sold 100 of them. It became quite clear that the only way IWC would survive was via unusual timepieces.
The Journey of Creating a Perpetual Calendar for a Wristwatch