Perpetual calendar

Perpetual calendar

Langematik-Perpetual
with perpetual calendar

The calendar display of a mechanical watch is called "perpetual" if it automatically updates the date, the day of the week, the month, and the moon phase displays. It not only takes into account the different durations of the months in the course of a year but also "knows" which years are leap years. The complex mechanism is controlled by so-called cams.

A perpetual calendar is an extraordinary exercise in the design and manufacture of this complication.