Audemars Piguet's Perpetual Calendar Models: An Introduction to Their Mechanisms and History

Audemars Piguet, a prestigious luxury watch brand, has devoted a great deal of time and effort to the development of perpetual calendars since its founding. This article explains the history and achievements of Audemars Piguet and the perpetual calendar, as well as the main models equipped with them.

Calendar Basics

There are several types of calendar functions found in luxury watches. Among them, there are two that are the most complex, and we will explain their characteristics and differences.

Annual calendar means once a year

A function called an annual calendar is a more sophisticated version of the standard date display function.

With the typical calendar function of a mechanical watch, when crossing over into a short month (a month without the 31st), you must manually advance the date from "30" to "1".

However, because annual calendars determine the length of the month and advance the date, they only need to be adjusted manually at the end of February, when the number of days changes due to leap years. Since they only need to be adjusted once a year, the name "annual" means "once a year."

Perpetual calendar

A calendar mechanism that requires even less adjustment than an annual calendar is the perpetual calendar. It does not require adjustment on March 1st and will continue to function automatically for approximately 100 years.

This mechanism is said to have been invented in 1795 by the renowned genius watchmaker Abraham-Louis Breguet (1747-1823), and is considered one of the three most complex mechanisms in the world due to its intricacy.

The Gregorian calendar (established by Pope Gregory XIII in 1582), which is currently the most widely used calendar in the world, has the rule that years divisible by 4 are leap years, years divisible by 100 are common years, but years divisible by 400 have a leap day.

Therefore, with a perpetual calendar, manual adjustments are required at 2100, 2200, 2300, etc., but few people will ever need to do this.

The perpetual calendar may seem like an improved version of the annual calendar, but the annual calendar is a relatively new mechanism that was created around the year 2000.

Audemars Piguet and the Perpetual Calendar

Audemars Piguet, one of the most renowned Swiss luxury watch brands, has been focusing on the development and evolution of the perpetual calendar since its founding.

Let's take a look at the history of Audemars Piguet's perpetual calendar, its specialty, and its current evolution.

The world's first leap year wristwatch was produced

At the beginning of the 20th century, pocket watches with perpetual calendars were already available, and Swiss watchmakers had also produced wristwatches with calendar functions, but for a long time wristwatches at that time lacked the ability to handle leap years.

In 1955, Audemars Piguet became the first in the world to equip a wristwatch with a perpetual calendar that accommodated leap years, marking a groundbreaking milestone in watchmaking history.

In 78, Audemars Piguet produced the Ref. 5548, which featured a distinctive stepped bezel, and it became a huge hit. It can be said to be a masterpiece that had a major impact on the industry thereafter.

Complexity and sophistication continue to evolve

The Royal Oak Perpetual Calendar, launched in 2015, is a model that demonstrates the ongoing evolution of Audemars Piguet's perpetual calendar.

The perpetual calendar boasts extremely sophisticated calendar functions, including an in-dial that displays the month, day of the week, and date, a moon phase display at the 6 o'clock position that shows the phases of the moon, and a third hand in the center that indicates the week number.

Another notable feature is the highly advanced technology used to incorporate a perpetual calendar into the thin movement, which is just 4.31mm thick.

Main models equipped with this

We will introduce watches equipped with a perpetual calendar from Audemars Piguet, taking a look at their other functions and designs. Please note that all of the models introduced here are produced in limited numbers and are therefore difficult to obtain.

CODE 11.59 by Audemars Piguet Perpetual Calendar

In 2019, Audemars Piguet added the new "CODE 11.59 by Audemars Piguet" collection to its lineup for the first time in a quarter of a century.

At first glance, it appears to have a round shape, but the octagonal middle case gives the design a sense of Audemars Piguet's DNA.

The perpetual calendar model is equipped with the in-house movement Cal. 5134, which has a power reserve of approximately 40 hours and is water resistant to 30 meters. The dial, which resembles a starry sky made of aventurine glass, also exudes the dignity befitting a luxury watch.

Royal オーク パーペチュアル calendar

This model is a perpetual calendar version of Audemars Piguet's flagship model, the Royal Oak.

Equipped with the in-house movement Cal. 5134, it displays the time with excellent visibility on the dial, featuring the tapestry design that characterizes the Royal Oak.

The moon phase plate is made of aventurine, and the moon, which has been laser-etched to create a realistic shadow, is also captivating.

Royal Oak Offshore Grande Complication

The Royal Oak Offshore, a derivative series of the Royal Oak, also has a model equipped with a perpetual calendar. This is a complication equipped with a complex mechanism. In addition to a perpetual calendar and moon phase, it is an ultra-complex model equipped with mechanisms such as a split-second chronograph and minute repeater.

In particular, the minute repeater, which announces the elapsed time by chiming, is highly rare among complex mechanisms and is an element that further enhances the value of this model.

The case is made of lightweight, scratch-resistant ceramic, which gives it a texture not found in other luxury watches.

Understanding the mechanism will make it even more enjoyable

Among the calendar functions incorporated into high-end mechanical watches, the perpetual calendar is the most complex and high-performance mechanism.

Audemars Piguet was the first in the world to equip a wristwatch with a perpetual calendar that accommodates leap years, and has continued to develop perpetual calendars that are increasingly complex and sophisticated.

Learn how this complicated mechanism, considered one of the world's three greatest complications, works and experience its intricacy with an Audemars Piguet model.