What are the display functions of the moon phase?

The moon is one of the objects worshipped by the ancients. It was also the first human guide to measure time. And until a few decades ago, people have been using it as one of the means of night lighting. It controls the tides of the ocean and even affects human emotions. For the watch industry, the display of the phases of the moon is not surprising.

Although the moon phase display function is not so complicated, it can add a bit of fun to the mechanical watch, so that the watch has a sense of mechanical complexity that men generally like.

The phases of the moon are related to the indications of the moon. Its technical requirements are simple and the precision requirements are also very generous. The moon phase display is relatively independent from functions such as chronograph and perpetual calendar.

In general, the moon phases are based on a 29.5-day cycle (i.e. the conjunct month) to show the state of the moon on the moon phase card. This moon card has two moons (patterns) with 59 teeth on the edge. The error caused by this mechanism is so small that it can be ignored as far as the moon phase display function is concerned. The precise rotation period of the moon is 28 days, 12 hours, 44 minutes and 2.9 seconds.

The display of the moon phase is usually a window of a specific shape dug out on the dial and displayed with the face of the moon on the moon card. This particular shape consists of a semicircular arc and two small circular arcs. This elaborate shape, combined with the moon on the Moon card, tells us more accurately what the moon looks like at the beginning or end of a cycle.

There is usually a moon phase adjustment button on the case. The moon phase display is relatively independent from functions such as chronograph and perpetual calendar.

Blancpain is more prominent in terms of moon phases. Its 6395 movement was introduced in 1983. This watch marks a revival in the art of mechanical watchmaking. The watch has several functions that are highly praised by watch lovers. In the hour scale circle, there is a display of the 31 days of the long month. Below 12 o'clock is the display of the month and day. Above 6 o'clock is the famous "Slanted-eyed Moon Man" surrounded by Venus, and above the crescent is the time of this lunar cycle (29.5 days in total).

This watch holds a record that its moon phase disc is the smallest in the annual calendar. A few years later, the 6395 was replaced by Blancpain's own automatic movement, the 1150. The latter has a power reserve of 100 hours, which is one of the important features of Blancpain watches.

In 2003, to celebrate the 20th anniversary of the 6395 movement, Blancpain successfully launched two limited edition moon phase automatic watches (dividend gold version and platinum version). And the automatic rotors of the movements of the two watches are designed as "crescent faces" to commemorate the lovely man in the moon on the 6395 movement 20 years ago.