IWC Schaffhausen’s Portugieser Eternal Calendar, reference IW505701, won the Aiguille d’Or at the 2024 Grand Prix d’Horlogerie de Genève (GPHG). Its headline distinction is a 400-year gear designed to account mechanically for Gregorian leap-year exceptions that ordinary four-year calendar cycles do not handle.
What won the 2024 GPHG Aiguille d’Or?
The 2024 Aiguille d’Or—the GPHG’s top award—went to IWC Schaffhausen for the Portugieser Eternal Calendar. The award announcement was dated 13 November 2024. The GPHG model record identifies the watch as reference IW505701, launched in April 2024; IWC introduced it at Watches and Wonders Geneva on 9 April 2024. IWC’s award announcement and the GPHG model record document the result and model details.
What makes its calendar “secular”?
The Gregorian calendar usually adds a leap day every four years. A century year is an exception: it is not a leap year unless it is divisible by 400. That means a calendar following only the familiar four-year cycle would need correction at certain century boundaries.
IWC calls the Portugieser Eternal Calendar its first secular perpetual calendar. Its added 400-year gear encodes the Gregorian exceptions by skipping three leap years across four centuries. According to the GPHG model record, the first such skip is in 2100. IWC describes the synchronized calendar displays as advancing through a mechanism operated using the crown. IWC’s explanation and the GPHG record describe the gear and its calendar rule.
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Does “eternal” mean it works forever?
No. “Eternal” is the model name, not a promise of an unlimited calendar range. IWC says the calendar calculates correctly until at least 3999, while noting that no official decision has been made on whether 4000 will be a leap year. The calendar’s stated rule therefore has a defined limit in the information IWC provides; it should not be read as a guarantee beyond that.
What does the Double Moon display claim?
IWC says the Double Moon phase display would theoretically deviate by one day from the Moon’s orbit after 45,361,055 years. The company’s 2024 launch release rounded this to 45 million years. This is a theoretical manufacturer specification, not an independently established long-term performance result. IWC’s award announcement gives the more precise figure.
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What are the key specifications of IW505701?
| Specification | GPHG model record |
|---|---|
| Case | Platinum |
| Diameter and thickness | 44.4 mm diameter; 15 mm thick |
| Strap and buckle | Leather strap; folding buckle |
| Movement | Self-winding mechanical |
| Power reserve | 168 hours (seven days) |
| Frequency | 28,800 vibrations per hour |
| Listed functions | Hours, minutes, seconds, date, day, month, year, moon phases, power-reserve indicator and perpetual calendar |
| Price shown in the record | CHF 150,000 including VAT; this is the GPHG record’s listed price, not a verified current quote or a universal price |
These are the launch-era details in the GPHG model record; they do not establish present stock or pricing in a particular market.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What is inside the watch?
IWC places the movement in its 52000 calibre family. The brand’s product information describes a Pellaton winding system, two barrels providing the listed 168-hour reserve, and ceramic components in high-stress parts. These are manufacturer-stated movement details. IWC’s Singapore product page provides that additional movement information.
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- Silicone watch strap soft and dust-resistant , comes with a quality stainless steel buckle, which is made of stainless steel.
- Please measure the width of your watch lug before ordering. It is important that your watch's lug width is the exact width of the band you select.
- Softness is moderate, wear very comfortable,Compression molding, sturdy and ,Wearable strap/wrist strap,suitable for original watch.
- Comfortable Fit: Soft, skin - friendly rubber conforms to wrist curves. Multiple adjustment holes ensure a perfect fit for all wrist sizes, offering stable, non - tight wear.
- Easy to insert and remove,very suitable for your watch.
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