IWC has been making perpetual calendars since Kurt Klaus engineered the first one in 1985. For forty years, that complication carried a quiet provision until you let the watch run out of its power reserve, at which point correction was required in a sequence to prevent damaging the mechanism. While IWC had already improved that by allowing the user to set the perpetual calendar via the crown many years ago, the ProSet mechanism, which debuted at Watches and Wonders Geneva 2026, removes that provision entirely as the Perpetual Calendar ProSet can be adjusted both forward and backward via a single crown position, making calendar adjustments as simple and intuitive as setting the time.
The IWC Big Pilot's Watch Perpetual Calendar ProSet Le Petit Prince variant—ref. IW339601—, which we reviewed and photographed at the show —pairs this engineering breakthrough with the midnight-blue gradient sunray dial that has defined the Saint-Exupéry editions since 2013, now marking twenty years of IWC's collaboration with the author's estate. And by the way, Le Petit Prince is one of our all-time favorite books, and every adult with an inner child should read it in their lifetime.
Things to Know About the Watch
The 42.9 mm case is white zirconium oxide ceramic, which is lighter than steel, harder, and highly scratch-resistant. The contrast between the white case and the deep blue gradient dial is sharper and more arresting in person than any press image conveys. The crown and caseback ring are stainless steel, with the screw-down crown maintaining 100-meter water resistance.
The ProSet calendar module is the headline: a fully gear-based architecture protected by five patents that allows both forward and backward corrections through a single crown position, the same position used to set the time. Many of its components require the LIGA process—a high-precision microstructuring technique combining lithography and electroplating—to manufacture at the required tolerances. The result is a perpetual calendar that behaves the way all perpetual calendars should have from the start.
As it is the norm for IWC for a decade, the perpetual calendar displays day of the week, date, month, and moon phase across four subdials, with the four-digit year display between 7 and 8 o'clock—among the most practically useful details on any perpetual calendar dial. The Double Moon display shows the lunar phase simultaneously in both hemispheres, with the re-engineered gear train achieving a deviation of just 1 day over 1,040 years.
The white rubber strap is equipped with the EasX-CHANGE system for tool-free swap.
The Movement
The IWC-manufactured Calibre 82665 integrates the ProSet module into the Big Pilot's proven perpetual calendar architecture. The Pellaton winding system, reinforced with virtually wear-free ceramic components, delivers a 60-hour power reserve. Through the sapphire crystal back of the display case, one can admire ‘The Little Prince’ — Le Petit Prince — on a pink-gold medallion affixed to the oscillating weight.
On the Wrist & Price
The ceramic case delivers immediately on its material promise as the watch is perceptibly lighter than the steel Big Pilot at the same diameter, and the smooth white surface reads as a premium material choice rather than a technical substitute. Under the usual bad lighting at Palexpo, where Watches and Wonders takes place, the blue gradient held its depth convincingly, deepening toward the periphery and drawing attention to the subdial architecture at the center.
Setting the calendar backward—something no traditional perpetual calendar permits without a service visit—worked exactly as described: intuitive, immediate, and without risking damage to the mechanism. This is the most practical perpetual calendar IWC has produced in forty years of building them, dressed in the most recognizable dial the brand has made in the last twenty years.
Sticker Price USD 41,600. For more information on IWC, click here.
