One caliber, several faces

Is it possible to predict the future? Since the 18th century, watchmakers have found their own way to glimpse what lies ahead. No magic, no esoteric rituals, and certainly no horoscopes! Instead, miniature gears of remarkable precision act as mechanical oracles. The complication they created does not foresee destiny, but anticipates days, months, and years with the rigor of a mathematician. Thus, the perpetual calendar—like the one housed in the Calibre 7138 unveiled this year by Audemars Piguet—knows the calendar until the year 2100, without ever making a mistake.

The 423 components of the selfwinding movement come together within a compact 29.6 mm architecture. This concentration of modern engineering brings complexity to serve simplicity of use. All adjustments are made solely via the crown, without the need for additional correctors, offering a significantly enhanced user experience.

Keen to preserve the robustness of the mechanism, the Manufacture has chosen to forbid any adjustment during the critical date-change phase. This no-correction zone, clearly indicated by a red arc between 9 p.m. and 3 a.m., ensures the integrity of the movement and the longevity of the perpetual calendar.

In addition to flawlessly orchestrating the display of the weeks, day, date, astronomical moon, months and leap years, the Calibre 7138 stands out for its ability to contribute, on the dial side, to an ultra-legible and harmonious scenography of temporal information—guided by geometry and symmetry.

The crown, featuring four positions, allows for intuitive adjustment of all time indications. In its first position, it winds the movement. Pulled out one notch further, it enables date adjustment by turning clockwise, while counterclockwise rotation sets the month and leap-year cycle. In the third position, the hour hand can be easily placed on the desired indication. Finally, when the crown is pushed back one notch, the day, week, and moon phase can be adjusted according to the chosen direction of rotation.

In a traditional construction, the functions of a perpetual calendar rely on three distinct levels within a movement. In the Calibre 7138, all functions are integrated on a single level. “The end-of-month cam is integrated into the date wheel, while the month cam is combined with the month wheel,” explains the Manufacture. The result? The movement does not exceed 4.10 mm in height. This significant advantage expands the possibilities for integration into slimmer cases.

To ensure the readability of the numerous indications, the positions of the subdials have been revised. The information is now displayed according to European conventions. The day is shown at 9 o’clock, the date progressively at 12 o’clock, and the month at 3 o’clock. The week numbers appear on the chapter ring. The moon phases benefit from a realistic depiction based on a NASA photograph. At full moon, the Earth’s satellite is perfectly centered on the 12 o’clock axis, completing the overall harmony.

An evolution of the Calibre 7121 and heir to the patented innovations of the Calibre 5133, the Calibre 7138 embodies the continuity and refinement of Audemars Piguet’s savoir-faire. With its technical performance and architecture designed for reliability, it has become a major asset in powering new references that are highly sought after by collectors. The limited editions of 150 pieces each, unveiled to mark the Manufacture’s 150th anniversary, offer a striking demonstration of this.