What is a Perpetual Calendar Watch? 

Also known as quantième perpétuel, a perpetual calendar is a mechanical watch that is programmed to automatically take into account how many days there are in a particular month, including 29 days in February during leap years.

Along with time, day, date, month, and leap year cycle, perpetual calendar watches also display the moon phase. Impressively, this watch will always show these displays correctly as long as it’s kept wound. A perpetual calendar watch does not need to be adjusted (as long as it keeps running) until 2100, which is when the next leap year will be skipped.

In short, a perpetual calendar is the crown jewel of all calendar watches. These are some of the most complex mechanical watches to make and a hallmark of high-horology brands such as Patek Philippe, Vacheron Constantin, Audemars Piguet, IWC, Breguet, Jaeger-LeCoultre, A. Lange & Söhne and others.

A tremendous amount of work goes into keeping everything correct when there are so many calendar fluctuations to account for. Watchmakers sometimes go a step further by pairing the perpetual calendar with other complications such as a chronograph, tourbillon, or minute repeater to create grand complication timepieces. 

From a brief history to explaining how it works and outlining some of the best variations available, here’s everything you need to know about perpetual calendar watches.

Brief History of the Perpetual Calendar

The oldest known perpetual calendar watch was a pocket watch made by Thomas Mudge in 1762. Mudge is best known for the invention of the detached lever escapement, which is considered one of his most celebrated innovations and greatest improvements to watchmaking. 

It was not until over a century later, in 1889, that Patek Philippe filed a patent for a perpetual calendar watch mechanism for pocket watches and pendant watches. This mechanism provided immediate jumps in days, dates, months, and lunar phases. It took another 40 years until the perpetual calendar movement was modified to fit into a Patek wristwatch in 1925.

Learn more: Patek Philippe, History of One of the World’s Top Watchmakers

In 1929, Breguet designed the first perpetual calendar wristwatch with a purpose-built movement. Other watchmakers soon followed suit; for example, Jaeger-LeCoultre introduced its first wristwatch with the complication in 1937. In 1941, Patek Philippe launched the first serially produced perpetual calendar wristwatches: the ref. 1526 and the chronograph version ref. 1518. 

In 1955, Audemars Piguet launched reference 5516, which was the first perpetual calendar wristwatch with a leap-year indicator. In 1985, IWC released the Da Vinci Perpetual Calendar, where, for the first time, all indicators were controlled by the winding crown rather than several separate pushers and buttons.

Learn more: The History of Audemars Piguet

Watchmakers continue to evolve the centuries-old mechanism by developing modern movements with new-and-improved features. An exceptional example is the MB&F Legacy Machine Perpetual Calendar, which eliminates the flaws of conventional (and often delicate) perpetual calendars.

How Does a Perpetual Calendar Work? 

Inside your perpetual calendar watch hides a plethora of gears. Some of these gears turn multiple times per second, others only once every four years or more. Most perpetual calendar watches have separate mechanisms for the date, month, day, and other calendar indicators.  It’s a massive network of interconnected pieces where gears for different indicators trigger one another. Using ridges, gaps, and dents on the gears, the watch is able to know the different days of the year.

See it on the Wrist: Audemars Piguet Royal Oak Perpetual Calendar Black Ceramic

Furthermore, the perpetual calendar watch typically shows a lunar cycle, which is every 29.5 days or so. Some watchmakers treat the lunar cycle as 59 days to help get around the added complexities of a 29.5-day moon phase. Higher-end watches will be precision milled to show the exact lunar cycle, while some of the less expensive models will not.

One of the drawbacks of some perpetual calendar watches is that they can be quite complicated to re-adjust (given all the indications) if they do run out of power, which is why it may be worth getting a watch winder to store them in.

Variations of the Perpetual Calendar

Perpetual calendar watches or quantième perpétuels, are available in many variations. While traditionally featured in dress watches, these days it’s not uncommon to find luxury sports watches or avant-garde timepieces furnished with the complication. What’s more, perpetual calendar chronographs are very popular within certain watch-collecting circles. 

Read more: Patek Philippe’s New Duo of Perpetual Calendar Split-Second Chronographs – The 5204G & 5373P

Dials will vary on how to display all the calendars, generally featuring several sub-dials or a mix of windows and sub-dials.

Dress Watches

A dress watch fitted with a perpetual calendar complication is the classic choice. They often feature precious metal cases, decorative dials, and superbly decorated movements. Many of them have ultra-thin movements too to keep cases nice and slim. Some of our favorite dressy perpetual calendar watches include:

• Patek Philippe ref. 5327
• Patek Philippe ref. 5320
• Audemars Piguet Code 11.59 Perpetual Calendar
• Vacheron Constantin Patrimony Perpetual Calendar Ultra-Thin
• Breguet Classique 5327
• Jaeger-LeCoultre Master Ultra Thin Perpetual Calendar 
• A. Lange & Söhne Langematik Perpetual
• IWC Portugieser Perpetual Calendar 
• F.P. Journe Quantième Perpétuel
• MB&F Legacy Machine Perpetual EVO

Sports Watches

As sportier watch silhouettes became more popular, fine watchmakers began pairing them with impressive complications including the perpetual calendar. Some notable sporty perpetual calendar watches include:

• Patek Philippe Nautilus 5740/1G
• Audemars Piguet Royal Oak Perpetual Calendar
• Vacheron Constantin Overseas Perpetual Calendar Ultra-Thin
• Jaeger-LeCoultre Polaris Perpetual Calendar
• Girard-Perregaux Laureato Perpetual Calendar
• IWC Big Pilot’s Perpetual Calendar
• Bulgari Octo Finissimo Perpetual Calendar
• Panerai Luminor Perpetual Calendar

Don’t Miss: Lionel Messi’s Nautilus Perpetual Calendar

Chronographs

As mentioned, perpetual calendar chronographs are some of the most coveted variations available, combining two impressive complications into one fantastic timepiece. A few standout perpetual calendar chronographs include:

• Patek Philippe 5270
• Patek Philippe 5204
• Vacheron Constantin Traditionnelle Perpetual Calendar Chronograph
• IWC Da Vinci Perpetual Calendar Chronograph
• Hublot Big Bang Unico Chronograph Perpetual Calendar
• Chopard L.U.C Perpetual Chrono

Related Content: Patek Philippe Introduces New Gem Set 5271P Complications

A Forever Favorite

Well over 250 years after Thomas Mudge developed his groundbreaking calendar complication, perpetual calendar watches are still going strong.

While we may be used to electronic devices keeping tabs on the time and date, it shouldn’t be taken for granted that a perpetual calendar wristwatch can do that mechanically and in perpetuity – no electrical current, internet connection, charger, or battery in sight. This tiny but mighty mechanism perfectly illustrates what fine watchmaking can achieve.

More from this series:
What is a Chronograph?
What is a GMT Watch?
What is a Dive Watch?
What is a Tourbillon Watch?
What is a Minute Repeater Watch?