Making its high-complication debut at Watches and Wonders 2026, the new Patek Philippe Cubitus Perpetual Calendar 5840P in platinum represents a seismic shift for the Maison.

Patek Philippe has broken the mould this time.

It places a fully skeletonised grand complication inside a bold, rounded-square case. Crafted from platinum 950, the 45mm case is the ultimate stage for a movement that is as much a horological feat as the Zenith El Primero.

Whether scouring the market to buy a Patek Philippe or tracking the most disruptive timepieces of the year, such as the new Rolex Oyster Perpetual 36 “Jubilee Dial” or the TAG Heuer Monaco, ref 5840P-001 is has many exciting elements such as

Hold tight, as Chrono Hunter looks at everything you need to know about the Patek Philippe Cubitus Perpetual Calendar 5840P

The Art Of Transparency: Skeletonised Complexity

The real magic of this lies in its refusal to hide anything. 

By opting for a skeletonised layout, Patek invites the wearer into the heart of the perpetual calendar mechanism. 

The blue dial is essentially a blue and gold mechanical landscape, where blue PVD-treated bridges provide a deep, contemporary contrast against the movement’s intricate gear train.

The Blue Pulse

The mainplates and bridges are treated with a rich blue PVD finish, creating a striking backdrop for the gold leaf-shaped hands.

Mechanical Depth

Every component of the perpetual calendar has been hand-finished, ensuring that from every angle, this execution catches the light with traditional haute horlogerie flair.

Modern Anchor

There’s a navy blue composite strap with matching platinum fold over clasp that despite its high-complication status, makes it firmly in the "sports-luxe" category a la Audemars Piguet Royal Oak.

The Heart of the Machine: Calibre 28-28 Q SQU

To power this cuboid titan, Patek has introduced calibre 28-28 Q SQU. 

This isn't a movement they simply "squashed" into a square; it was engineered specifically to fill the case geometry, maximising the visual impact of the skeletonisation.

Official Specs: Patek Philippe Cubitus Perpetual Calendar 5840P 

Conclusion

Whether you view the Patek Philippe Cubitus Perpetual Calendar 5840P as a masterclass in modern geometry or a polarising "square-peg" in a round-hole there is no denying the technical ambition of the skeletonised calibre 28-28 Q SQU. 

By successfully merging their most prestigious complication with a dense, prestige-heavy platinum 950 chassis, the maison has delivered something that doesn't just rest on its laurels, it lap-preps them for the next century.

Clearly, they have created a modern icon that makes even the most sought-after discontinued Patek Philippe watches look conservative by comparison. 

In a world where many timepieces look like they were designed by committee, Patek has doubled down on its own unique vision. It’s bold, it’s expensive, and it’s unapologetically Patek, a level of wrist-dominance that rivals even the most headline-grabbing celebrity collections. 

(Speaking of knockouts, you might want to see how this compares to Jake Paul’s $7 million Jacob & Co. Billionaire).

Ready to buy a Patek Philippe to crown your collection or need to sell a watch to fund this blue-blooded beast? Chrono Hunter offers the most secure way to transact with multiple offers from our verified network of luxury retailers.

Time is up this year at Palexpo. But we're counting down once again, to see what the stable of Thierry Stern has up their sleeve in 2027!

Discover, hunt, buy, sell.

Images: (Unless otherwise stated) Patek Philippe

Further Reading:

A complete review of the Patek Philippe Nautilus 5990

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