The IWC Da Vinci Perpetual Calendar Chronograph reference 3750, launched in 1985, was the first mechanical chronograph with a perpetual calendar built into a wristwatch of its size. It is based on the Valjoux 7750 automatic chronograph with a perpetual calendar module developed by IWC’s Kurt Klaus, and it shows the date, day, month, four-digit year and moon phase. The case was an unusual one, made of ceramic and titanium, with a black dial; the calendar is set entirely with the crown and is programmed to run until the year 2499.

Klaus’s module made the watch practical: a single crown could adjust every indication, which removed the fiddly correction pushers of earlier perpetual calendars. The hi-tech case was the work of the era’s interest in new materials, and the watch was produced in small numbers with several case variants, so sources differ in sizes and production figures.

Collectors count the 3750 as a milestone of 1980s watchmaking and the start of the modern IWC complication line. The original ceramic Da Vinci is no longer made, though IWC has relaunched the Da Vinci name in later collections.