Five Moon Phase Masterpieces to Enjoy on Long Autumn Nights

　Moon phases are very popular. A typical moon phase display uses a 59-tooth disc, twice the length of the lunar cycle (29.5 days), to depict two moons. This is based on the fact that the average lunar cycle is approximately 29.53 days. This is the standard moon phase display, adopted by Abraham-Louis Breguet in the 18th century.

　However, 29.53 days = 29 days, 12 hours, 44 minutes, and 2.88 seconds, meaning that approximately 44 minutes are truncated per cycle. This accumulates to an error of one day every three years. This can be considered a "slight difference." In reality, it is difficult to notice the difference. This is why many moon phase watches use this 59-tooth system. However, of course, there are also models that aim for even greater accuracy. In recent years, an error of one day every 122 or 125 years has become the norm, and even models with a high accuracy of one day every 1000 years or more have appeared.

　Here, we have carefully selected five masterpieces from among the various moon phase models. How about enjoying the moon phase while admiring the real moon on a long autumn night?

Hermès "Arceaux L'Heure de la Lune"

This much talked about model was unveiled in Geneva this year. The moon in the southern hemisphere is positioned at 12 o'clock, and the moon in the northern hemisphere at 6 o'clock. The two subdials displaying the time and date complete one revolution around the dial every 59 days, creating a double moon phase model that displays the phases of two moons. The moons are made of molybdenum, with Pegasus depicted on the southern hemisphere and the actual lunar surface on the northern hemisphere. Two models with dials, meteorite and aventurine, are available, each limited to 100 pieces worldwide.

H. Moser & Cie. "Endeavour Perpetual Moon"

This is a top-class ultra-high precision moon phase with an error of just one day in 1027 years. Moreover, while a normal moon phase only moves the disc once a day (i.e., one advance), this moon phase is constantly moving in conjunction with the hour hand, and is only off by 0.23 seconds per day from the actual movement of the moon. This is the latest model, and its "concept" specification, with nothing written on the dial, makes the moon phase stand out even more.

A. Lange & Söhne "Lange 1 Moon Phase"

Almost all A. Lange & Söhne moon phase watches have an error of just one day every 122.6 years, which means they reproduce the lunar cycle with 99.998 percent precision. In addition to its high precision, this moon phase watch features a separate sky disc that rotates once every 24 hours, displaying a blue sky during the day and a starry sky at night, also functioning as a day and night indicator.

IWC Portugieser Perpetual Calendar

The IWC Da Vinci Perpetual Calendar, released in 1985, is a historic masterpiece of perpetual calendars. One of its innovative features was its high-precision moon phase, which is only accurate to one day every 122 years. The Portugieser Perpetual Calendar is an evolved version of this, boasting ultra-high precision, with only an error of one day every 577.5 years. Another major attraction is the double moon phase, which displays the moon as seen in both the northern and southern hemispheres as a mirror image.

Blancpain "Villeret Perpetual Calendar 8 Days"

Blancpain is one of Switzerland's most prestigious brands, widely known for its pure, classic style, exclusively producing mechanical and round watches. The Blancpain Moon Phase, with its classic moon face design, is a major attraction. This is a perpetual calendar with a long eight-day power reserve. The beauty of the Grand Feu enamel dial is also stunning.