perpetual calendar

Franck Muller has been incorporating the perpetual calendar, one of the classic complicated mechanisms of mechanical watches, into his wristwatches since the very beginning. As the name perpetual calendar, also known as the "perpetual calendar," suggests, the watch itself keeps time according to the actual calendar so that it can accurately show the calendar up to the year 2100. The movement perfectly incorporates not only long and short months, but also leap years that occur once every four years. A series of gear trains that display seconds, minutes, and hours are linked to gears for the date, day of the week, month name, and leap year, realizing the calendar function, so no artificial correction is required. A wristwatch with this ultra-complex mechanism incorporates everything from the smallest unit of seconds to the largest unit of years for people to know time, and even displays the moon phase to tell the age of the moon. This extremely complex mechanism makes it seem as if a small universe exists within the wristwatch.