It’s nearly a century since Patek Philippe began creating complicated calendars for wristwatches.
The No. 97975 was the first perpetual calendar wristwatch in the world, and was swiftly followed by a successor in 1930 that would define the standard for advanced calendars in a wristwatch, with four counters that displayed the day, date, month, moonphase, and running seconds.
Not long after, Patek Philippe would introduce another watch, the Ref. 96, fitted with a retrograde date display, moonphase, and two apertures for the day and month indicators. The Ref. 96, of course, continues to live on today as the Calatrava, with its well-balanced proportions that has shaped Patek Philippe’s round watches for over 90 years.
An Iconic Calendar
This practical and highly legible way of displaying the complete calendar has become a perennial at Patek Philippe, presented in some of its most handsome timepieces such as the regal Ref. 6002R Sky Moon Tourbillon, with a hand-engraved case and Grand Feu champlevé and cloisonné enamel dial. On this dial, the retrograde date ring and minute track are painted in gold with the words “Patek Philippe Geneve” in a large bold font. Inside this ring, applied hour indexes are placed along with four indicators at each quarter: the leap year window at 12 o’clock, month at 3, moonphase at 6, and day of the week at 9.
While the Sky Moon Tourbillon has a very classic bearing, the same design in the Ref. 5316/50P-001 Grand Complication offers a far more modern interpretation, with an architectural take on the retrograde date perpetual calendar. Set on a smoky blue metallised sapphire crystal with a black gradient rim, the retrograde date display is printed on a thin sliver of deep black onyx. Faceted hour markers are applied around the date display, with three windows at each quarter, and a moonphase and running seconds counter at 6 o’clock. Like all classic Patek Philippe watches, the tourbillon is visible from the back of the watch.
In 1941, Patek Philippe introduced not one, but two perpetual calendar models, the Ref. 1518 and Ref. 1526, with a new calendrical layout that further simplified its display. This meant there was more space on the watch dial, allowing its design to breathe. The Ref. 1518 also made use of this additional negative space to add a bicompax chronograph to the watch.
Today, the two models live on as the Ref. 5270 (Perpetual Calendar Chronograph) and Ref. 5320 (Perpetual Calendar) respectively. But their evolution does not end there. Following on from the Ref. 5320, Patek Philippe introduced the Ref. 5236P-001 in 2021, which offers a fully in-line instantaneous perpetual calendar with a moonphase display and running seconds at 6 o’clock. The further simplification of this design with a single-window display makes for even easier reading of the complete date, using four discs to indicate the day, date (in tens and ones), and the month. Sitting on the same plane, the Caliber 31-260 PS was refined to ensure sufficient power at all times for the midnight date jump.
The Caliber 31-260 PS QL features 3 new patents specially designed for the perpetual calendar, ranging from a ball-bearing system used for the display, to an anti-double-jump feature that prevents the date from bouncing when adjustment is taking place, and an immobilisation system for the date jump between ‘31’ and ‘1’. These innovations demonstrate how functional and intelligent design is at the core of every Patek Philippe perpetual calendar watch.
The perpetual calendar is a marvel of mechanical watchmaking, able to keep up with a century (or in a secular perpetual calendar, 10,000 years) of date-keeping. The logic in designing this using purely mechanical parts is impressive. While Patek Philippe does create perpetual calendar watches featuring this one high complication, it more frequently combines it with other equally impressive designs such as the minute repeater or chronograph. In the case of the Ref. 5208, it’s both.
across the upper half of the dial. In the last 15 years, there have been several iterations of the two models in precious metals and elegant dials. The Ref. 5208R-001 illuminates this design with a moonphase counter with running seconds at 6 o’clock, chronograph totalisers at 3 and 9, plus leap year and day/night apertures within those counters. The efficiency of its design, while allowing plenty of room for the dial to breathe, is matched by exquisite finishing on the case, applied indexes, and the self-winding R CH 27 PS QI movement driving the watch.
In 1996, Patek Philippe once again experimented with the advanced calendar by inventing a new complication – the annual calendar. Requiring just one adjustment each year for the last day of February to the first of March, the annual calendar was a practical complication welcomed by collectors and watchmakers alike.
But beyond that, the annual calendar complication was also an opportunity for Patek Philippe to introduce new innovations from its Advanced Research Department. These included its first silicon escape wheel in the Ref 5250G, the Spiromax balance spring in Silinvar in the Ref. 5350J, and the Pulsomax escapement (with an escape wheel and lever in Silinvar) in the Ref. 5450P. Today, these innovations are part of every Patek Philippe watch, but back in 2005, they were bold introductions for the watchmaker.
This year, the Annual Calendar appeared in the Aquanaut Luce case, combining the sporty elegance of the watch with the practical calendar function. In this model, Patek Philippe also adjusted the organisation of the dial, with the moonphase complication sitting just above the brand’s logo, while the calendar indicators feature the month at 9 o’clock, date at 6 and day at 3, a reverse from the usual Patek Philippe calendar.
More importantly, this is a sporty calendar model that wears well for everyone, with a neutral grey-blue colour palette and composite strap that will suit casual or formal looks. It demonstrates how Patek Philippe is evolving its complications and watches with current trends and styles, in a carefully curated manner.
The advanced calendars of Patek Philippe are a valued addition to any collection.