When the full moon rises in the clear night sky where crickets sing, It truly feels like the season of autumn has arrived. The moon brightening the deep blue night sky creates a unique atmosphere on its own. The moon that appears on a small dial also serves as a mood maker that brightens the ambiance. The moon on the dial is a function called the Moon Phase, Which visually displays the phases of the moon. Sometimes, The moon is personified by drawing a face on it when expressing the details of the Moon Phase. Some may call this a Moon Face, But this is incorrect. The correct term for the moon in watch functions is Moon Phase.

History

Time and date are the results of our ancestors' studies of celestial phenomena. The method of counting days is also a product completed based on records of the sun rising and setting and the moon appearing and disappearing in the sky.

The Moon Phase, Which displays the ever-changing appearance of the moon, Is also a function created based on celestial phenomena. It is known that the origin of the Moon Phase was to check the date or for navigation. When the weather was continuously cloudy or bad during navigation and it was impossible to check the position or phase of the moon, The Moon Phase was used to determine this. If it was necessary to check the tides by observing the moon's phase, The Moon Phase was very useful. The exact history of the Moon Phase function is not clearly known, But according to various sources and opinions, It is said to have been found in European table clocks from the 16th century.

The first Moon Phase wristwatch, Said to have been introduced by Patek Philippe in 1925 ⓒ oracleoftime.com

After that, The Moon Phase function could be found in Breguet's pocket watches in the 18th century, And although it is not clear for wristwatches, The moon on the dial can be seen in watches produced around the 1930s and 1940s.

Display of the Moon Phase

The actual lunar cycle takes about 29 days, 12 hours, 44 minutes, And 28 seconds. Roughly, It can be said to have a cycle of 29.5 days. Therefore, The Moon Phase is made based on a 29.5-day cycle. Two symmetrical moons are placed on a gear with 59 teeth (29.5 days x 2) for display. The reason for using a pair of moons instead of just one is that it is impossible to make 29.5 teeth. Since half a tooth cannot be implemented, Two are combined to make 59 teeth.

The actual lunar cycle of 29 days, 12 hours, 44 minutes, And 28 seconds and the rounded value of 29.5 days gradually diverge over time. Just as the difference between the 365 days we use and the Earth's orbital period accumulates and is corrected by adding a leap year every four years, The Moon Phase also accumulates a few minutes of error over time. Watch companies have worked to reduce this error and have added correction devices to the Moon Phase function. Some watchmakers have reduced the error to just one day in 122 years, Making it almost imperceptible in a lifetime. Not satisfied with this, Some have achieved practical 'zero' error, With a deviation of one day in 45 million years, Which is almost impossible to notice in a human lifetime, Thereby realizing an extremely accurate Moon Phase.

Blancpain Villeret Date Moonphase © ablogtowatch.com

However, In modern times, The practicality of the Moon Phase has greatly diminished. Just as time can be easily checked anywhere in daily life, The phase of the moon can be easily found by searching the internet. Even in navigation, There is no longer a need to rely on the position or shape of celestial bodies as in the past. Nevertheless, The use of the Moon Phase has not decreased. This is because it still plays a significant role as a mood maker on the dial. In addition, The Moon Phase is increasingly appearing in watches designed for beauty, Such as ladies' watches.

Various Moon Phase Watches

IWC Portugieser Eternal Calendar

The irregularity of the Gregorian calendar causes imperfection in perpetual calendars that follow it. IWC overcame this imperfection with a mechanism exposed between 4 and 5 o'clock on the dial, Completing the Portugieser Eternal Calendar in pursuit of eternity.

IWC Portugieser Eternal Calendar
© italianwatchspotter.com

Beneath the dial, Which features transparency thanks to the use of glass, Is a Moon Phase mechanism that pursues accuracy comparable to a perpetual calendar, Driving a double Moon Phase decorated with guilloché. This simultaneously displays the appearance of the moon as seen from both the southern and northern hemispheres, And with an accuracy of one day in 45 million years, The Moon Phase function also pursues eternity.

Omega Speedmaster Moonphase

Omega Speedmaster Moonphase in Sedna gold
with Alligator Strap © ablogtowatch.com

The Speedmaster, Known as the Moonwatch, Originates from the 'Moon landing, ' where Apollo 11 astronauts wore the watch on their wrists as they set foot on the moon. However, This has little direct connection to the Moon Phase function. The Speedmaster Moonphase, A derivative of the Speedmaster, Features a Moon Phase between the chronograph counters, As its name suggests. The Moon Phase disk, Which realistically depicts the surface of the moon against a sparkling night sky, Is a distinctive feature. As the disk rotates, It uses a cloud-shaped window to display the actual shape of the moon. This is the most common type of Moon Phase display.

Lange & Söhne Lange 1 Moon Phase

Vintage is generally considered to be at least 30 years since discontinuation. For example, Based on the Submariner, Models such as Ref. 168000, Which was produced for a short period just before Ref. 16610LN, Or earlier models like Ref. 16800, Could be considered the starting point of vintage.

Lange & Söhne – Richard Lang Terraluna L096.1 </br>
© monochrome-watches

Lange & Söhne, Which has demonstrated expertise in astronomical functions with watches like the Richard Lange Perpetual Calendar Terraluna, Also shows diversity and technical perfection in Moon Phase watches. The Lange 1 Moon Phase appears similar to a typical Moon Phase. The moon and stars visible through the cloud-shaped window do not seem much different from others.

A. Lange Sohne Lange 1 Moon Phase </br>
© monochrome-watches

Piaget Altiplano Ref. G0A47105

The Altiplano, With a case diameter of 36mm, Expresses a splendid Moon Phase throughout the entire watch. Although the designer's intention is unknown, The combination of blue aventurine and a guilloché pattern on the mother-of-pearl dial expresses light, Reminiscent of moonlight shining at night. Inside, The Moon Phase is decorated with a crescent-shaped diamond setting. The aventurine disk moves to create the shape of the moon, Highlighting the luxury of the material. The self-winding Cal. 580P movement features a crescent-shaped rotor, Allowing the moon to be seen from any angle, Demonstrating attention to detail.

Felix

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Watch Columnist