According to Cambridge Dictionary, perpetual means continuing forever in the same way. Perpetual calendar, often referred as QP or Quantieme Perpetuel, is a complication usually with a complete calendar display (date, day, month, moon-phase indicator and leap year) that when is set correctly and constantly running will not require any adjustment. Well in most case until the year 2100, as it is an exceptional non-leap year.

Perpetual calendar complication is extremely complex, and it can consists of hundreds of parts. It was first invented in the 1700s by an English watchmaker, Thomas Mudge. To me, perpetual calendar is the very first attempt to create a smart watch, it has an ability to correctly count the date of the month, with a 30 or 31 days months, 28 days in February and 29 days in February in the leap year. And keep in mind all these were done mechanically without any technological aid.

Due to its complexity, in the earlier days perpetual calendar watches were usually made to order. And it is only towards the mid 20th century some manufacture started to have a serially produced perpetual calendar wristwatch.

*Audemars Piguet 25657BA Quantième Perpétuel and Breguet 3050BA Classique Perpetual Calendar*

In the late 1970s to mid 1980s in the midst of quartz crisis some manufactures (Audemars Piguet, Breguet and Patek Philippe) braved into the possibility of reviving the world of high horology by introducing their “mass-produced” perpetual calendar wristwatch as part of their main collection. With these watches, the market started to appreciate the value of mechanical watches again.

*Patek Philippe 3940J Perpetual Calendar First Series*

Most perpetual calendar watches has three or four register display on the dial. And with the progression of time, some are made with more intricate dial and some are even skeletonised to give us a glimpse of not only into the complex mechanism but also the high level of finish and decoration of the movement.

*Audemars Piguet 25657PT Quantième Perpétuel “Tuscan” and Vacheron Constantin 43032 Automatic Perpetual Calendar Skeleton*

And towards the 1990s we start to see more creativity in creating the perpetual calendar display with different dial layout as opposed to the traditional three or four register display of the perpetual calendar watches.

*Breguet 7717 Perpetual Calendar with linear display and Patek Philippe 5050J Perpetual Calendar with retrograde date*

Today most of the major high-end watch manufacture has at least a perpetual calendar in their line up and even so it never ceased to impress me, especially to think of how useful the complication is and how such complex mechanism can be achieved in such small package. And to me that is what high-horology is about.

Time is Perpetual