(Reminder: The word saros comes from Greek, which is an astronomical term, meaning that the sun, the earth and the moon complete a relative position operation cycle every 18 years. )
2. Calendar display mechanism
As mentioned above, there is another important month display mechanism that we can't ignore, because the calendar mechanism itself was born by distinguishing large and small months. If there is no month display, the calendar display cannot verify which month date it displays.
3. Annular calendar instantaneous jumping mechanism
The popularity of calendar display in wristwatches is largely attributed to Rolex and ETA factory's extensive application of circular calendar display in their products, which gave birth to many classic movement models of large three-hand calendars, and gradually made the large three-hand calendar become the industry standard of Japanese wristwatches. There are two common forms of circular calendar display mechanism, one is slow climbing type, and the other is instantaneous jumping type.
As the name implies, the former is a "chronic patient" who may take several hours to complete a calendar change, while the latter is an "impatient patient" who can complete a calendar change in just a few seconds, which is just an instant in the eyes of the wearer.