On the occasion of the WATCH ART Grand Exhibition – Milan 2026, Patek Philippe redefines the boundaries of Grand Complications with the release of Reference 5978P-010. Issued in a strictly limited edition of 120 pieces, this platinum timepiece reinterprets the Manufacture’s iconic perpetual calendar chronograph by incorporating, for the first time, an instantaneous perpetual calendar mechanism driven by the new manual-wind caliber CH 29-535 PS QI.
A New Chapter in the Legacy of Grand Complications
Ever since the legendary reference 1518 first combined a chronograph and a perpetual calendar in a wrist watch back in 1941, this combination has remained one of Patek Philippe’s most sought-after hallmarks. Following the consolidation of caliber CH 29-535 PS Q within reference 5270 starting in 2011, the Geneva Manufacture takes a step further by fusing the manual-wind chronograph architecture with an instantaneous aperture display arranged in an arc.
The instantaneous perpetual calendar in this piece relies on the patented mechanism originally introduced in reference 5207 and further developed in grand complications 5208 and 5308. Its architecture enables all four display discs (day, date, month, and leap-year cycle) to jump simultaneously in a mere 30 milliseconds, even with as little as ten hours of power reserve remaining. To achieve this technical feat, the system incorporates a large 15-piece articulated yoke and a dual-spring structure acting in opposite directions to maintain consistent energy delivery during end-of-month transitions.
Caliber CH 29-535 PS QI: High Manual-Wind Architecture
The mechanical heart of the 5978P comprises 500 components, each meticulously hand-finished. Its chronograph section retains the traditional nobility of a column wheel topped with a polished cap and a horizontal clutch, incorporating six patented innovations to optimize meshing, reduce wear, and refine synchronization.
Beating at a frequency of 28,800 vibrations per hour (4 Hz), regulated by a Gyromax® balance wheel with a Breguet balance spring, the movement delivers a power reserve ranging from 55 to 65 hours with the chronograph disengaged. Through the sapphire crystal display back, engraved with the commemorative inscription “Patek Philippe Milano 2026”, one can admire the movement’s exquisite architecture bearing the Patek Philippe Seal.
Platinum Calatrava Case and Sunburst Navy Blue Dial
The Calatrava case measures 42 mm in diameter and 14.24 mm in thickness, fully crafted from hand-polished 950 platinum. It is distinguished by its concave bezel, delicately pierced lugs, and a discreet brilliant-cut diamond set into the case flank at 6 o’clock.
The sunburst navy blue dial features a black gradient rim surrounding a subtly textured center. The calendar readouts are framed by white-gold apertures positioned along an upper arc with Italian calendar discs, accompanied by azuré sub-dials for the chronograph and small seconds, a moon-phase display at 6 o’clock, and secondary apertures for day/night and leap-year indications. Dynamic touches include red-lacquered chronograph hands and a navy composite strap accented with contrasting stitching inspired by the colors of the Italian flag.
⚙️ Technical Summary
Patek Philippe Instantaneous Perpetual Calendar Chronograph (Ref. 5978P-010)
Grand Complication housed in a 42mm platinum Calatrava case. Sunburst navy blue dial with an arc-shaped instantaneous perpetual calendar display in Italian. Powered by the manual-wind caliber CH 29-535 PS QI featuring 500 components and the Patek Philippe Seal. Limited edition Milano 2026 of 120 pieces.
Technical Specifications
| Specification | Patek Philippe Ref. 5978P-010 |
|---|---|
| Reference | 5978P-010 (Milano 2026 Limited Edition of 120 pieces) |
| Case | 950 platinum, concave bezel, diamond at 6 o’clock, engraved sapphire exhibition caseback |
| Dimensions | 42.0 mm diameter × 14.24 mm thickness |
| Dial | Sunburst navy blue with black gradient, Italian aperture calendar displays, white gold indices and dauphine hands |
| Water Resistance | 30 meters (3 ATM) |
| Movement | Caliber CH 29-535 PS QI, manual-wind mechanical, 500 components |
| Frequency | 28,800 vph (4 Hz), Gyromax® balance, Breguet balance spring |
| Power Reserve | Min. 55 hours – Max. 65 hours (chronograph disengaged) |
| Functions | Column-wheel chronograph, instantaneous perpetual calendar (day, date, month, leap year), day/night indicator, and moon phases |
| Strap | Navy blue composite material with textile motif, red stitching, and platinum fold-over clasp |
