The mellifluous chimes of the Portugieser Eternal Calendar ring in a new epoch for IWC Schaffhausen. This secular perpetual calendar, an engineering tour de force unfettered by the capriciousness of our Gregorian calendar, glides effortlessly through the centuries with chronometric certitude.

With meticulous artistry, IWC’s master horologists have crafted a mechanical program that calculates the vagaries of leap years with unerring accuracy. The calendar’s 400-years gear, an ingenious module of just eight parts, makes but one revolution every four centuries, skipping three leap years along its orbit. This technical marvel, guided by the steady tempo of its manufacture movement, will keep perfect pace with the celestial ballet until at least the year 3999.

Yet IWC ventures beyond, touching the very limits of eternity. The Double Moon phase display, an entrancing celestial dance, will diverge merely one day from the moon’s sidereal journey in 45 million years—a span far beyond earthly reckoning. This astonishing precision is born of a reduction gear train of such exacting proportions that only a simulated cosmos of 22 trillion permutations could conceive it.

This Portugieser serenades the ages with peerless technical brilliance encased in classical elegance. A frosted white glass dial shimmers below, bearing hand-mounted appliques and floating numerals. Intricate finishes adorn the platinum case while a black alligator Santoni strap embraces the wrist. The timeless allure of the Eternal Calendar stems from the marriage of engineering prowess and aesthetic mastery—the twin pillars of the IWC legacy.

$155,000.