IWC’s April 2024 update to the Portugieser Perpetual Calendar 44 reworked the case profile and dial finishing while retaining the collection’s seven-day automatic movement and crown-set perpetual calendar. Four 18-carat gold versions launched, with a Double Moon display that IWC says deviates from the Moon’s orbit by one day after 577.5 years.
What changed on the updated IWC Portugieser Perpetual Calendar 44?
Unveiled at Watches and Wonders Geneva in April 2024, this was a redesign of the Portugieser Perpetual Calendar 44—not a new 2026 Portugieser. IWC described the watch as completely re-engineered. The visible changes include a slimmer case ring and side profile, box-glass sapphire crystals on both the front and back, and glossy dials with layered lacquer. IWC’s 2024 launch announcement says each dial is built with 15 layers of transparent lacquer, then ground and polished.
Monochrome Watches reports a 44.4 mm case diameter and 14.9 mm thickness. The diameter is 0.2 mm larger than its predecessor, while the water-resistance rating increased from 30 m to 50 m. That rating is not a claim that the watch is designed for diving. Monochrome’s April 2024 first look provides those measurements and comparison points.
What is the difference between the four IW5037 references?
The four launch versions share the same movement and calendar functions. Their differences are case metal, dial color, strap, and reported launch price:
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- Model IW391031
| Reference | Case | Dial | Strap | April 2024 launch price |
|---|---|---|---|---|
| IW503701 | 18-carat Armor Gold | Silver Moon, silver-plated | Brown alligator | CHF 45,000, reported by Monochrome Watches |
| IW503702 | 18-carat Armor Gold | Obsidian black | Black alligator | CHF 46,000, reported by Monochrome Watches |
| IW503703 | 18-carat white gold | Horizon Blue | Gradient light-blue calfskin | CHF 46,000, reported by Monochrome Watches |
| IW503704 | 18-carat white gold | Dune | Black alligator | CHF 46,000, reported by Monochrome Watches |
IWC says Armor Gold’s modified microstructure makes it harder and more wear-resistant than conventional 5N gold. That is the manufacturer’s material claim, not an independent comparative test.
How does the calibre 52616 and perpetual calendar work?
All four references use IWC-manufactured calibre 52616, an automatic movement with Pellaton winding, two barrels, and a seven-day power reserve. IWC lists 385 movement components and ceramic components in the winding system; the oscillating mass is solid gold. Monochrome reports a frequency of 28,800 vibrations per hour.
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The calendar displays are synchronized and set through the crown. IWC says the perpetual-calendar mechanism has 81 parts in a module 1.5 mm high. It accounts for different month lengths and adds a leap day every four years. Under the Gregorian calendar, century years are not leap years unless divisible by 400; IWC says a minor adjustment is therefore required in years such as 2100 or 2200.
How accurate is the Double Moon display?
The Double Moon display depicts the Moon’s phase as seen from the Northern and Southern hemispheres. IWC states that the display deviates from the Moon’s actual orbit by one day after 577.5 years. This is the manufacturer’s stated precision figure, not an independently measured result.
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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.
What was the launch price, and what is known about current pricing?
Monochrome reported April 2024 launch prices of CHF 45,000 for IW503701 and CHF 46,000 for each of IW503702, IW503703, and IW503704. Those are historical launch prices in Swiss francs. The available sources do not establish current prices in any region, present stock, or resale values.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Is the 2024 Portugieser a ProSet perpetual calendar?
No. IWC’s announcement of 14 April 2026 introduced the IWC-ProSet perpetual calendar in Big Pilot’s Watch editions, using calibre 82665. IWC describes that separate mechanism as gear-based and adjustable forward or backward, with a moon-phase display that deviates by one day after 1,040 years. The announcement does not identify the 2024 Portugieser IW5037 references as ProSet watches. IWC’s 2026 ProSet announcement concerns those Big Pilot’s Watch editions, not this Portugieser update.
Quick Recap
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- Timeless styling that effortlessly takes you from work to play.
- Analog Month/Day/Date, Moonphase Indicator
- Two-Tone Stainless Steel
- Spherical Mineral Crystal
- 100 Meters Water Resistant and 5 Year Limited Warranty
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
