At Watches and Wonders 2026, IWC Schaffhausen introduced a significant technical update to its calendar complication: the Perpetual Calendar IWC-ProSet. While IWC has been synonymous with crown-controlled perpetual calendars since Kurt Klaus’s 1985 Da Vinci, this new “ProSet” system introduces a functionality that has long been a challenge for mechanical calendars—bidirectional adjustability.
The ProSet Innovation: Bidirectional Control
The primary technical breakthrough here is a completely synchronized, gear-based design. Historically, most perpetual calendars could only be adjusted forward; if you overshot the date, the watch often required a trip to a watchmaker or had to wait for time to “catch up”.
The ProSet system allows the wearer to adjust the calendar both forward and backward using only the crown. This is achieved through a redesigned internal architecture featuring multiple functional layers and a system of flexible, extendable, and retractable fingers that engage with the calendar gears. This eliminates the need for case-side corrector buttons or navigating digital-style setting menus.
Enhanced Moon Phase and Mechanical Logic
IWC’s engineers also updated the reduction gear for the moon phase display. The new calculation increases the precision of the indicator so that it will deviate from the actual lunar orbit by just one day every 1,044 years. The display remains the brand’s signature “Double Moon,” showing the phase for both Northern and Southern hemispheres.
The mechanical program remains fully autonomous. It accounts for the varying lengths of months and the leap year cycle via a complex month-length wheel. To manufacture these intricate geometries with the necessary precision, IWC utilized the LIGA process—a micro-structuring technique combining lithography, electroplating, and molding.
The Three Debut Editions
The new ProSet mechanism debuts in three distinct versions of the Big Pilot’s Watch.
The Big Pilot’s Watch Perpetual Calendar ProSet Le Petit Prince (Ref. IW339601) features a 43-millimetre white zirconium oxide ceramic case and a deep blue dial with a gradient finish. The numerals and indices are printed in white on the dial, while the hands are rhodium-plated and filled with Super-LumiNova. This watch is fitted with a white rubber strap featuring the EasX-CHANGE® system.
The Big Pilot’s Watch Perpetual Calendar ProSet Le Petit Prince (Ref. IW329601) is executed in a 42 mm stainless steel case. This version features a deep blue dial with rhodium-plated appliques and comes on a stainless steel bracelet, though it also includes an additional blue rubber strap. Like the ceramic version, it utilizes the EasX-CHANGE system for quick strap swaps.
Both “Le Petit Prince” models include specific aesthetic details, such as an engraving on the case back ring and a gold-plated medallion on the rotor depicting the Little Prince. All three models allow the movement to be viewed through a transparent sapphire glass case back.
The Big Pilot’s Watch Perpetual Calendar ProSet (Ref. IW329602) is crafted from 18-carat 5N gold and measures 42 mm in diameter. It features a dark olive green dial with applied gold indices and numerals. This edition is fitted with an olive green buffalo leather strap and a 5N gold pin buckle.
Caliber 82665
All three debut models are powered by the IWC-manufactured 82665 calibre. Key technical specifications of the movement include:
- Automatic Winding: Features the Pellaton system, which uses bidirectional movements of the oscillating mass.
- Wear Resistance: High-stress components of the winding system, such as the automatic wheel and clicks, are made from zirconium oxide ceramic.
- Modern Materials: Equipped with a silicon hairspring and a nickel-phosphorus escapement.
- Power Reserve: 60 hours.
For more details, visit www.iwc.com.
