IWC Portugieser Perpetual Calendar

The Portugieser Perpetual Calendar is IWC's masterpiece. Kurt Klaus conceived the module in the 1980s with an elegance that still astonishes: every indication — date, day, month, the four-digit year and the moon — advances from a single mechanical programme requiring no correction until 2100, and the entire calendar is set through the crown alone. The double moonphase deviates by one day in 577.5 years.

Reference: IW503302
Movement: Automatic, in-house calibre 52610 with Pellaton winding
Power reserve: approx. 168 hours (7 days)
Case: 18k rose gold, 44.2 mm
Complications: Perpetual calendar, four-digit year, double moonphase
Water resistance: 30 m
Year: 2026 — Full set