MACHINE LEARNING

The mechanical calendar has been perfected over the last 100 years; it remains a challenge that invites multiple watchmaking and engineering approaches. We get into the nuts and bolts of how the perpetual calendar gets the job done

- ASHOK SOMAN

It may surprise you to learn that the perpetual calendar is probably the simplest of all the high complications to make and to understand. That is a bold assertion, to be sure, especially if you arrived here after the lengthy missive on the evolution of our contemporary calendar. Well, we will be walking that back immediately. Confusingly, the perpetual calendar (or various executions of it) can be particularly challenging for watchmakers, and the results vary from highly complicated to heavily pared down. On the other hand, it can also be rather ho-hum, with established movements having proven track records for decades. It would be centuries but wristwatches have only been with for so long.

This can be understood with some context: while the mechanical perpetual calendar does impressive work, it has been through a period of relative inactivity, which we are arguably still living through. To be clear, by inactivity here we mean very little in the way of new ideas, just as base mechanical movements themselves saw virtually no improvements since the debut of the workhorse ETA 2892 calibre. Consider that the Swiss lever escapement is dominant in mechanical watchmaking, and that system had been refined more than 100 years ago (see our escapement specials for more, via Luxuo.​com).