Description

The present reference is the Patek Philippe Perpetual Calendar Chronograph ref. 3970EP-019, a fourth-series iteration executed in platinum and distinguished by an original black dial appointed with factory diamond hour markers.

Introduced in 1986, the reference 3970 marked a transformative chapter in Patek Philippe’s grand complication lineage, succeeding the celebrated reference 2499 that had defined the maison’s perpetual calendar chronographs for over three decades. Crucially, the 3970 established a departure in movement architecture, adopting a refined ébauche based on the historic Lemania 2310 to replace the Valjoux calibres utilized across the preceding half-century. Across its four generations, the fourth series is distinguished by its crisp, pointed baton hands and matching indexes—or, as showcased in this configuration, factory-set brilliant-cut diamonds that create dramatic contrast against an ebony lacquer ground.

The 36 mm platinum case preserves the model’s classical proportions, defined by stepped, concave bezels and fluted, flared lugs. Punctuating the case at 6 o’clock is the discreet Top Wesselton diamond set between the lower lugs, signifying its precious platinum execution.

The glossy black dial serves as an arresting backdrop for the high-complication display, punctuated by applied diamond hour markers that impart modern glamour to an otherwise traditional arrangement. Twin apertures beneath 12 o’clock present the day and month, while the subsidiary registers organize the intricate calendar and timing indications: a 30-minute chronograph counter combines with the leap-year cycle at 3 o’clock, a radial date dial frames the moon-phase display at 6 o’clock, and running seconds share the 9 o’clock sub-dial with a 24-hour day/night indicator.

Beating within is the manufacture’s hand-wound Calibre CH 27-70 Q, a column-wheel chronograph movement integrating an instantaneous perpetual calendar mechanism. Operable through the screw-down sapphire exhibition caseback, the calibre exemplifies Geneva Seal craftsmanship with its chamfered, mirror-polished steel levers, circular Côtes de Genève, and free-sprung Gyromax balance wheel.

Patek Philippe – Bio

Patek Philippe & Co. was founded in 1839, located in Geneva and the Vallée de Joux. It designs and manufactures timepieces and movements, including some of the most complicated mechanical watches. It is considered by many experts and aficionados to be one of the most prestigious watch manufacturers.
In 1868, Patek Philippe made their first wristwatch, which was sold on November 13, 1876 to the Hungarian Countess.
It is the last independent, family-owned Genevan watch manufacture with uninterrupted operating history spanning nearly 180 years.