The Patek Philippe Perpetual Calendar
Ref. 5320G-011

The invention of the Perpetual Calendar

In addition to the chronograph and minute repeater, the perpetual calendar is another of the great complications that make a watch a masterpiece of fine watchmaking and a true luxury item.

The invention of the first pocket watch with a perpetual calendar is attributed to the English watchmaker Thomas Mudge in 1764, as an answer to the complex system of the Gregorian calendar, which has months of 28, 30 and 31 days, with an extra day in February during leap years, which occur every four years.

The exceptional mechanical memory of 1461 days offered by the perpetual calendar complication takes all these variables into account and only allows a manual adjustment to be made on 1 March 2100, since, exceptionally, that year will not be a leap year.

The rule states that secular years (e.g. 1700, 1800, 1900, 2100) that do not add up to a whole number when divided by 400 are not leap years. This is why, in 2100, the calendar will have to be manually reset to 28 February.

1925. A year that marked the history of Patek Philippe

In 1925, the Manufacture broke new ground with the presentation of the Patek Philippe 97975, the world's first wristwatch with a perpetual calendar which, like almost all great inventions, has a curious history. In fact, this movement dates back to 1898, when Patek created it to be mounted on a lady's pendant watch. That watch didn't sell and, a quarter of a century later, this perpetual calendar movement, designated no. 97975, was mounted in a yellow gold wristwatch. With a 34.4 mm diameter case (case no. 22 033) featuring hand-engraved lugs and flanks, an artistic tradition that continues in some current references. This treasure trove of watchmaking history is kept in the Patek Philippe Museum. In 1941, the first reference produced in small series was launched, the very rare 1518, a Perpetual Calendar Chronograph, which also debuted the combination of these two complications.

The Ref. 5320 reimagined

An ode to visual balance and legibility, the perpetual calendar model with the reference 5320 was designed in 2017 in a white gold case with a cream lacquered dial. Its vintage style is reinterpreted in 2022 in a new white gold version with gilded opaline rose gold dial. The beauty of this version lies in its balanced case, with a classic diameter of 40 mm and a height of 11.13 mm, combined with the elegant salmon pink dial.

The military inspiration remains, in the Arabic numerals and luminescent hands, in sophisticated contrast to the dial, with an opaline rose gold plating in a smooth texture, a rare finish that gives it a soft colour.

The calendar is presented in the manner characteristic of Patek Philippe perpetual calendar watches since 1941, with a double window in a day/month line at 12 o'clock and the date indicated by a hand surrounding the moon phase aperture at 6 o'clock. These are complemented by two round apertures: one for the day/night indication between 7 and 8 o'clock; and the other for the leap year cycle between 4 and 5 o'clock - both useful for adjusting the calendar. The extremely precise moon phases require a correction of one day only once every 122 years.

Powered by a self-winding mechanical movement, the calibre 324 S Q is visible, like all its parts and finishes, through the sapphire crystal caseback.

A sophisticated perpetual calendar, specially designed for watch lovers and collectors, with a more relaxed and contemporary elegance, perfect for any occasion.