Portugieser Eternal Calendar Platinum Watch (IW505701)

Special Order at the IWC Schaffhausen Palm Beach Boutique

Call to Order (561)670-2920

The IWC Portugieser Eternal Calendar Ref. IW505701 combines an elaborately finished platinum case with a transparent white glass dial, seamlessly bridging Kurt Klaus's legendary perpetual calendar architecture with IWC's first secular calendar mechanism. Awarded the "Aiguille d'Or" at the 24th Grand Prix d'Horlogerie de Genève in November 2024, the Eternal Calendar stands as IWC's most ambitious statement yet on the mechanical measurement of time.

• Secular Perpetual Calendar: A newly engineered 400-year gear train allows the calendar to correctly skip three leap years every four centuries, calculating the date accurately until at least the year 3999 — a mechanical first for IWC.
• Double Moon™ Phase Display: A newly developed reduction gear train with three intermediate wheels drives a moon phase display so precise it will deviate from the moon's actual orbit by only one day after a world-record-breaking 45,361,055 years.
• Case & Strap: 44.4mm polished platinum case fitted with double box-glass sapphire crystals front and back, paired with a black alligator leather strap by Santoni and a platinum folding clasp.
• Dial: White glass dial produced through a multi-step process with a frosted underside and hand-mounted appliques, its transparency framed beneath the box-glass sapphire crystal.
• Movement: Powered by the automatic IWC-manufactured Calibre 52640 with the manufacture's signature Pellaton winding system, running on two barrels for a seven-day power reserve.