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What is the Perpetual Calendar in Watches? A Comprehensive Guide

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what is a perpetual calendar in watches

A perpetual calendar is a type of complication found in some high-end watches. It is designed to display the correct date perpetually, taking into account the varying lengths of months and leap years. With a perpetual calendar watch, the wearer doesn’t need to adjust the date manually, as the watch will do it automatically.

The first perpetual calendar wristwatch was a groundbreaking invention by Patek Philippe in the 1920s. This marked a milestone in horology, leading many other watch manufacturers, such as Audemars Piguet and Jaeger LeCoultre, to develop their own versions of the perpetual calendar complication, some even integrating it with chronographs, resulting in perpetual calendar chronographs.

A perpetual calendar watch can track several measurements of time with high accuracy, including seconds, minutes, hours, lunar phases, days, months, and even leap years in some cases. With its impressive functionality and precision, a perpetual calendar watch is a highly sought-after timepiece among watch collectors and enthusiasts.

What is Perpetual Calendar In Watches?

A perpetual calendar, a prestigious complication in the realm of luxury watches, is designed to display the correct date perpetually, embodying the intricacies of the Gregorian calendar including leap years.

Automatic Correction

The perpetual calendar mechanism automatically corrects for the different number of days in each month. It has a program that understands the number of days in February and adds the extra day during leap years. This means the watch will always show the right date, whether it’s February 28th or 29th.

Long Power Reserve

High-quality perpetual calendar timepieces have a long power reserve that can last up to several days when not worn. This ensures that even if the perpetual calendar pocket watches itself is left unworn for a day or two, it will still have enough power to continue tracking the date and month. If the power reserve depletes completely, the perpetual calendar mechanism may require resetting by a watchmaker to ensure all indications are correct.

Precise Craftsmanship

Perpetual calendar timepieces demonstrate the pinnacle of watchmaking artistry and precision. They require skilled craftsmen and hundreds of parts to create the intricate mechanism that powers the perpetual calendar function. The level of expertise and labor required to produce a perpetual calendar watch mechanism contributes to their prestige and higher cost.

Brief History of Perpetual Calendars

Perpetual calendar watches have a long and storied history dating back to the 18th century. The first perpetual calendar mechanisms were developed around 1700 by watchmakers such as Thomas Mudge. These early perpetual calendars were very complex, with many gears and parts that were difficult to produce and assemble.

In 1925, Rolex introduced their reference 1165, one of the first wristwatches to feature a perpetual calendar. This helped popularize the complication and make it more accessible to consumers. However, perpetual calendar watches were still quite expensive and labor-intensive to produce for many decades.

Significant advancements in perpetual calendar mechanisms and production occurred in the mid-20th century. In the 1950s, Patek Philippe created a “perpetual calendar module” that could be more easily fitted to existing watch movements. They also introduced new gear systems that were more efficient and required fewer parts.

These developments led to a boom in perpetual calendar watches from prestigious brands in the 1950s and 1960s, including Patek Philippe, Audemars Piguet, Vacheron Constantin, and others. Prices also started to decrease, though perpetual calendars were still quite expensive.

How do Perpetual Calendar Watches Work?

Audemars Piguet Royal Oak perpertual date watch

Perpetual calendar complications are one of the most sophisticated complications found in luxury watches. These watches are designed to automatically adjust the date, day, and month, taking into account the nuances of the various annual and perpetual calendars used, including leap years and month lengths. In this section, we will explore the different sub-components of the perpetual calendar complication.

Leap Year

A leap year is a year that has 366 days instead of the usual 365 days. It occurs every four years, except for years that are divisible by 100 but not by 400. A perpetual calendar watch takes this into account and adjusts the date accordingly. This is done through a complex mechanism that involves a four-year cycle.

Month and Day

The perpetual calendar complication also takes into account the varying lengths of months and adjusts the date accordingly. This is done through a series of gears and levers that work together to keep track of the correct number of days in each month. The day of the week is also displayed on the watch’s face, making it easy to keep track of important dates and appointments.

Moon Phase

Many Perpetual calendar timepieces also include a moon phase display. This displays the current phase of the moon, which is important for tracking tides, fishing, and hunting. The moon phase display complete calendar watches is often located on a sub-dial and can be adjusted by a pusher on the side of the watch.

Week and Day

Some perpetual calendar watches also include a week and day display. This displays the date displayed the current week’s number and the day of the week. This is useful for people who travel frequently or work in international business. The week and day display is often located on a sub-dial and can be adjusted by a pusher on the side of the watch.

Setting a Perpetual Calendar Watch: A Rare Occurrence

Setting a perpetual calendar watch can be a rare occurrence, thanks to the watch’s ability to automatically adjust for leap years and varying lengths of months. However, when it does become necessary to set a perpetual calendar watch, it can be a bit complicated and time-consuming. The watch’s complex mechanism requires precise adjustments to ensure that it will continue to accurately track time.

To set a perpetual calendar watch, the wearer must first consult the watch’s user manual to understand the specific instructions for their particular watch model. The process typically involves adjusting the watch’s various sub-dials and buttons to synchronize the time, date, month, and year.

One of the most important steps in setting a perpetual calendar watch is ensuring that the watch is set to the correct leap year cycle. Most perpetual calendars follow a four-year cycle, but some may follow an eight-year cycle. It is essential to confirm the correct cycle to ensure that the watch will accurately adjust for leap years. Another crucial aspect of setting a perpetual calendar watch is ensuring that the watch’s hands are set in the correct position. It is essential to avoid moving the hands backward, as doing so can damage the watch’s delicate mechanism.

Top Luxury Watch Brands with Perpetual Calendars

Patek Philippe

Patek Philippe is a Swiss watch manufacturer renowned for its exceptional craftsmanship and pioneering innovation in the world of watchmaking. Their perpetual calendar models are icons in the industry, revered for their complex mechanics and sophisticated design.

1. Patek Philippe Perpetual Calendar Ref. 5320G-011

Patek Philippe Perpetual 5320G-011

This watch features a day, date, month, leap-year cycle, and moon phase on a Rose-gilt opaline, charcoal gray gold applied numerals with a luminescent coating dial. Its Art Deco design is inspired by historical models from the 1940s and 50s. The Pre-owned price is $112,116.

2. Patek Philippe Perpetual Calendar Chronograph Ref. 5270/1R-001

Patek Philippe 5270 1R-001

It combines a chronograph and a perpetual calendar, driven by a manually wound mechanical movement, the Caliber CH 29‑535 PS Q. This watch showcases Patek Philippe’s command over complicated watchmaking. In addition to tracking the day, month, and leap year, it also provides a day/night display in apertures and tracks the date by hand. The pre-owned price of this watch is $170,927.

3. Patek Philippe Nautilus Perpetual Calendar Ref. 5740/1G-001

Patek Philippe Nautilus 5740 1G-001

This watch marries the sporty aesthetics of the Nautilus line with the sophistication of a full perpetual calendar chronograph. Powered by an ultra-thin mechanical self-winding movement, the Caliber 240 Q, this timepiece is a testament to Patek Philippe’s skill in creating highly functional yet elegant watches. In addition to day, date, and month, it also indicates the leap year and provides a 24-hour indication by hand. Selling at a pre-owned price of $239,863.

Audemars Piguet

Audemars Piguet, another Swiss watchmaker, is acclaimed for its avant-garde designs and technical mastery. Their Royal Oak and Royal Oak Offshore perpetual calendar models are particularly sought after.

1. Audemars Piguet Royal Oak Perpetual Calendar Ref. 26574ST.OO.1220ST.03

Audemars Piguet 26574ST.OO.1220ST.03

This Audemars Piguet Royal Oak offers a complete package of functionality and elegance with its perpetual calendar that includes week indication, day, date, astronomical moon, month, leap year indicator, and standard hours and minutes display. The pre-owned price of this timepieces is $138,719.

2. Audemars Piguet Code 11.59 Perpetual Calendar Ref. 26394BC.OO.D027KB.01

Audemars Piguet Code 11.59 26394BC.OO.D027KB.01

The Audemars Piguet Code 11.59 Perpetual Calendar Ref. 26394BC.OO.D027KB.01 is an exquisite embodiment of the brand’s dedication to superior craftsmanship and cutting-edge design. This watch represents the fusion of traditional horology with modern aesthetics, housing a perpetual calendar complication within an innovative and sophisticated timepiece. Selling at a pre-owned price of S$108,184.

3. Audemars Piguet Royal Oak Perpetual Calendar Ref. 26585CE.OO.1225CE.01

Audemars Piguet 26585CE.OO.1225CE.01

A feat of technical mastery, the Royal Oak Perpetual Calendar Openworked combines artistic openwork with the robust durability of black ceramics. This focus on clarity allows the essence of the perpetual calendar to shine through, demonstrating its excellence in both aesthetics and functionality. The Pre-owned price is $415,540.

Vacheron Constantin

Vacheron Constantin is one of the oldest and most esteemed watch manufacturers in the world. Their perpetual calendar models reflect their commitment to tradition, elegance, and technical excellence.

1. Vacheron Constantin Patrimony Perpetual Calendar Ultra-Thin Ref. 43175/000R-9687 

Vacheron Constantin Patrimony 43175 000R-9687

This watch exudes a timeless elegance, with a clean, minimalist dial featuring the day, date, month, and a precision moon phase. The pre-owned price for this model is $52,622.

2. Vacheron Constantin Traditionnelle Perpetual Calendar Ultra-Thin Ref. 4305T/000G-B948

Vacheron Constantin Traditionnelle 4305T 000G-B948

This model is an exquisite example of horological mastery. With its elegant 18K white gold case, this timepiece showcases the in-house Calibre 1120 QP, a self-winding movement that brings the perpetual calendar function to life. The perpetual calendar complication ensures precise display of the day, date, month, and often includes a charming moon phase indicator.

3. Vacheron Constantin Overseas Perpetual Calendar Ultra-Thin Ref. 4300V/000R-B064

Vacheron Constantin Overseas 4300V 000R-B064

This model combines sporty aesthetics with a highly complicated movement, all in an ultra-thin package. Despite its slim profile of just 8.10 millimeters, it houses an ultra-slim perpetual calendar that is designed to maintain accurate display until the year 2100. Adding to its aesthetic allure is a moon phase with a star-studded sky and two gold moons that complement the perpetual calendar work. The pre-owned price of this model is selling at $90,098.

Note: The pre-owned prices mentioned are estimated and subject to market fluctuations.

Annual Calendars vs. Perpetual Calendars

Annual Calendar

An annual calendar is a watch complication that displays the day, date, and month, and only needs to be adjusted once a year. It can distinguish between months with 30 and 31 days, but not February, which has 28 days in a standard year and 29 days in a leap year. Annual calendars are less expensive than perpetual calendar watches and are generally considered more practical for everyday use.

Perpetual Calendar

A perpetual calendar is a watch complication that can display the day, date, month, year, and even moon phase, and can automatically adjust for leap years. It is designed to keep track of time accurately until the year 2100, after which it will need to be manually adjusted. Perpetual calendar watches are more expensive than annual calendar watches and are considered to be one of the most sophisticated calendar watches.

Annual Calendar WatchPerpetual Calendar Watch
FunctionalityDisplays the day, date, and month. Adjusts automatically for months with 30 and 31 days but does not adjust for February.Displays the day, date, month, year, and sometimes the moon phase. Adjusts automatically for months with 30 and 31 days, February, and leap years.
Adjustment FrequencyNeeds to be adjusted once a year.Designed to keep track of time accurately until the year 2100, requiring manual adjustment only once every hundred years.
PrecisionHighly accurate.Considered more precise due to automatic adjustment for leap years.
PracticalityConsidered more practical for everyday use.Regarded as one of the most sophisticated calendar watches, less practical for everyday use due to their complexity and cost.
SuitabilitySuitable for those who want a complicated watch but at a relatively lower cost.Ideal for horology enthusiasts and collectors who value the mechanical ingenuity and precision involved.
CostGenerally less expensive than perpetual calendar watches.Typically more expensive due to their complex mechanisms and intricate design.


1. How Perpetual Calendars Keep Accurate Time Forever

Perpetual calendar watches use a complex system of gears, levers, and springs to keep track of time. The key to their accuracy lies in their ability to recognize the number of days in each month and to adjust accordingly. This is achieved through the use of a series of cams and gears that work together to advance the date display at the end of each month.

The mechanism that controls the perpetual calendar is powered by the watch’s movement, which is usually a self-winding mechanical movement. This means that the watch will continue to run as long as it is worn regularly, and the perpetual calendar will continue to keep accurate time without any intervention from the wearer.

One of the most impressive features of a perpetual calendar is its ability to account for leap years. Leap years occur every four years, with the exception of years that are divisible by 100 but not by 400. To account for this, perpetual calendar watches have a special mechanism that recognizes these exceptions and adjusts accordingly.

2. What Happens if a Perpetual Calendar Watch Stops?

If a perpetual calendar watch stops, it requires minimal adjustment via the winding crown to reset. Given their intricacy, brands like Audemars Piguet with their famed Royal Oak, and Patek Philippe with their perpetual calendar offerings, have made a name in the market.

Once the watch has been restarted, the calendar mechanism will need to be reset to the proper date. The watch owner will have to manually input calendar information like the current month, date, and year to resynchronize the perpetual calendar. Some Perpetual calendar timepieces may require resetting additional indications like the day of the week, moonphase, or year indicator.

Resetting a perpetual calendar watch after it has stopped can be an intricate process. It may need to be done by a skilled watchmaker to ensure all the perpetual calendar works and indications are properly set. If the reset is not done correctly, the perpetual calendar can become out of sync and provide inaccurate information until it is serviced.

3. Why Perpetual Calendar Watches Are Worth the Investment

Perpetual calendar watches represent an intersection of artistic beauty and technical ingenuity, contributing significantly to their status as treasured investments. From a pure financial perspective, their future value and price dynamics make them a worthy addition to any collection.

As wearable pieces of art and engineering marvels, high-end watches like those with a perpetual calendar complication often appreciate over time. Their demand in the luxury watch market remains high, which, coupled with their scarcity, drives their value upward.

Perpetual calendar watches are intricate and time-consuming to manufacture. The complexity involved in creating a watch that automatically accounts for leap years and varying month lengths, often with other complications added, means that production numbers are typically low. This scarcity inherently boosts their value.

Watches from esteemed manufacturers like Patek Philippe, Audemars Piguet, or Vacheron Constantin are known for their meticulous craftsmanship and brand prestige. These factors play a crucial role in maintaining and increasing the watch’s value over time.

Final Word

Perpetual calendar watches represent the epitome of watchmaking excellence, combining mechanical sophistication with enduring style. While an investment, their timeless allure, technical prowess, and potential for value appreciation make them worthwhile for any watch enthusiast or collector.

Key Takeaways

  • Perpetual calendar watches are known for their complex mechanism that accounts for the varying lengths of months and leap years, requiring minimal manual adjustment.
  • These high-end timepieces, while expensive, hold their value over time, making them a sound investment.
  • Prestigious brands like Patek Philippe, Audemars Piguet, and Vacheron Constantin are renowned for their exceptional perpetual calendar models.

At Watch Exchange, we understand the value and allure of a fine timepiece like a perpetual calendar watch. Whether you’re looking to start your collection, add a new piece, or exchange an existing one, we offer a wide selection of pre-owned luxury watches such as Rolex, Patek Philippe, Tissot, Sinn, Zenith, and other luxury timepieces. to suit your taste and budget. 

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