A new chapter for IWC’s perpetual calendar
Some complications remain tied to a single name down the decades. At IWC Schaffhausen, the perpetual calendar is inseparable from that of Kurt Klaus, whose brilliance came to the fore in 1985 with the Da Vinci Perpetual Calendar Chronograph (Ref. IW3750). With its elegantly logical, crown-controlled mechanism, the legendary watchmaker shaped the complication for several generations.
Forty years on, the Schaffhausen manufacture chose Watches and Wonders Geneva 2026 to unveil the next chapter in that story: the Big Pilot’s Watch Perpetual Calendar ProSet®. Building on Kurt Klaus’s pioneering spirit, IWC’s new generation of engineers has developed a completely reimagined architecture, protected by several patent applications, which fundamentally redefines how a perpetual calendar is set and operated.
A perpetual calendar that can be set forward and backward
This is the headline innovation of the new IWC release: the Perpetual Calendar ProSet can be adjusted just as easily forward or backward, from a single crown position. There is no need for separate corrector buttons, additional crown positions or cumbersome setting sequences.
While the dial retains the familiar appearance of the Big Pilot’s Watch, the internal mechanics have been entirely reworked. The movement now relies on a fully synchronised, gear-based system featuring multiple functional layers and flexible, extendable and retractable fingers. This architecture allows the patented quick-correction function to move the displays forward — or backward — in precise daily steps, with the simplicity of setting the time.
Programme wheel and micro-engineering: at the heart of the Perpetual Calendar ProSet.
A moon phase accurate to one day in 1,040 years
The manufacture’s engineers also recalculated the reduction gear driving the moon-phase display. The result: the indicator deviates from the moon’s actual orbit by just one day every 1,040 years, a level of precision that is unprecedented for the Maison. True to its style, IWC retains its signature Double Moon™ display, which shows the phase of the moon as seen from both the northern and southern hemispheres.
Each night, around midnight, the synchronised switching sequence advances the date, the day of the week and the moon phase in unison. The four-digit year display, another hallmark of IWC’s perpetual calendars, remains located between 7 and 8 o’clock.
Micro-engineering and the 82665 manufacture calibre
Behind this ease of use lies a remarkable feat of engineering. The 24-hour wheel, the programme wheel, the month length wheel and the moon-phase gears feature highly intricate geometries, produced using the advanced LIGA process — a micro-structuring technique combining lithography, electroplating and moulding — which makes it possible to integrate several functional layers into a single component.
The calendar module is incorporated into the IWC-manufactured 82665 calibre, beating at 4 Hz (28,800 vph), with 34 jewels and a power reserve of 60 hours. It combines a nickel-phosphorus escapement, a silicon hairspring and the highly efficient Pellaton winding system, whose most heavily stressed components are crafted from virtually wear-free zirconium oxide ceramic. The movement can be admired through the transparent sapphire glass case back and is meticulously finished with Geneva stripes and circular graining.
Transparent sapphire glass case back revealing the 82665 manufacture calibre — Ref. IW339601.
Three interpretations: ceramic, steel and red gold
This new complication is brought to life in three Big Pilot’s Watches 43, all powered by the same 82665 calibre.
- Big Pilot’s Watch Perpetual Calendar ProSet Le Petit Prince (Ref. IW339601) — 43 mm case in white zirconium oxide ceramic, deep blue dial with a gradient finish, rhodium-plated hands filled with Super-LumiNova®, white rubber strap with the EasX-CHANGE® system.
- Big Pilot’s Watch Perpetual Calendar ProSet Le Petit Prince (Ref. IW329601) — 42 mm stainless steel case, deep blue dial with rhodium-plated applied indices and numerals, five-link stainless steel bracelet with the EasX-CHANGE® system, supplied with an additional blue rubber strap that can be swapped without tools.
- Big Pilot’s Watch Perpetual Calendar ProSet (Ref. IW329602) — 42 mm case, crown and case back ring in 18-carat 5N red gold, dark olive green dial, applied gold indices and numerals and gold-plated hands filled with Super-LumiNova®, olive green buffalo leather strap with an 18-carat 5N red gold pin buckle.
Ref. IW329601 in stainless steel: five-link bracelet and additional blue rubber strap, interchangeable without tools thanks to the EasX-CHANGE® system.
Both Le Petit Prince editions feature the “Edition Le Petit Prince” engraving on the case back ring, as well as a gold-plated medallion on the rotor of the automatic winding system depicting the Little Prince on his asteroid — a charming nod to the most famous tale by Antoine de Saint-Exupéry, a pilot at heart.
A milestone for the Big Pilot’s Watch
With the Big Pilot’s Watch Perpetual Calendar ProSet, IWC does far more than simply expand its Pilot’s Watches collection: the manufacture reinterprets one of its most emblematic complications, making it more intuitive, more precise and resolutely forward-looking. To discover this new release and the full range of the Maison’s creations, visit our dedicated pages for IWC Schaffhausen and for the IWC Pilot’s Watches family.
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