IWC Watchmaker assembles the Portugieser Eternal Calendar (Ref. IW505701)

Inside the Eternal Calendar: Assembling the IW505701 Awarded the “Aiguille d’Or” at the 24th Grand Prix d’Horlogerie de Genève, the Portugieser Eternal Calendar IW505701 is IWC’s first secular perpetual calendar - a watch that measures time on an extraordinary scale. Its platinum 44.2 mm case houses the hand-wound 52640 calibre, featuring a 7-day power reserve across two barrels, a 400-year gear that automatically skips three leap years (years divisible by 100 but not by 400), and a Double Moon™ display accurate to one day in over 45 million years.