A moon phase watch with a mysterious charm. Feel the romance on your wrist.

The moon phase displays the phases of the moon on a watch dial. Unlike when it was invented and needed for navigation, the moon phase mechanism no longer has a practical need today, but the romanticism of the dial, which changes its appearance over time, is what makes it so appealing. Let's trace the history of the moon phase, which has progressed alongside scientific developments, and take a look at some of the recommended moon phase models available today.

A microcosm nestled in a watch: the "Moon Phase"

The moon phase is a feature that shows the waxing and waning of the moon on the dial. First, let's understand how the moon changes shape.

How the shape of the moon changes

A typical moon phase display features a small window through which the moon can be seen, with two full moons positioned on a full-sized disc depicting the night sky, allowing two lunar cycles to be seen in one revolution of the disc.

The number of teeth on the gear that rotates the disc varies depending on the model, but is usually 59. If the lunar cycle takes an average of 29.5 days, then having 59 teeth allows the disc to show two phases during one revolution.

The actual cycle of the moon's phases is slightly longer than 29.5 days, so a typical moon phase will have an error of one day every two to three years. However, there are also ultra-high-precision models that can be used for a lifetime without needing adjustment.

The history of the moon phase

The moon phase was originally developed as a mechanism for practical purposes such as checking the calendar and navigation. For example, even when it was cloudy for several days and the position and phases of the moon could not be seen, the moon phase could still be seen as if it were a tangible presence.

Nowadays, information about the phases of the moon is easily accessible on the internet. However, in the days when determining the phases of the moon depended on good or bad weather, it was extremely difficult to obtain accurate information at all times. For people for whom the phases of the moon and its position were important, moon phase information was an invaluable source of information.

Moon phases were first seen in table clocks from around the 16th century, but were incorporated into pocket watches in the 18th century and began to appear in wristwatches in the 1940s.

Good to know: A brand that captivates enthusiasts with its moon phase display

Many luxury watch brands now use moon phase displays. Here we will introduce three leading brands that make moon phase displays.

Breguet: Pioneer of the Moon Phase

Breguet is a brand whose history began in 1775 as a watch workshop established by Abraham-Louis Breguet. Breguet has left its mark on the history of watches by inventing numerous groundbreaking mechanisms, and has inherited the name of this genius watchmaker.

Breguet was also the pioneer of moon phases in pocket watches, with the classic "No. 5" from 1794 already featuring a moon phase display in the same style as we see today.

Breguet addressed the problem of fractional parts in the lunar cycle by depicting two moons on the disc and using 59 gear teeth to incorporate the actual phases of the moon onto the dial.

IWC Invents the Perpetual Moon Phase

IWC is a manufacture brand founded in 1868. It has gained popularity with its signature collections such as the Portofino, Portugieser, and Aquatimer.

The Caliber 50000 movement, released by IWC in 2015, incorporates gears with more teeth than conventional moon phase models. This mechanism significantly reduces the display error of the moon phase, achieving a theoretical accuracy of only one day every 577.5 years.

If you choose a model equipped with IWC's pride and joy, the perpetual moon phase, it would be a good idea to indulge in the romance of entrusting the magnificent count of time and the calendar, which spans several times the length of your lifetime, to your descendants in the distant future.

Zenith: The epitome of contemporary elegance

Zenith, which began its history in 1865, is a brand known for the world's first automatic integrated chronograph movement, the legendary "El Primero," which was released in 1969.

However, Zenith also has another signature movement: the "Elite," named after an in-house movement developed in the 1950s. The collection featuring this Elite is characterized by a minimalist, streamlined design that matches the design codes of mid-20th century watches with modernity. It truly embodies Zenith's contemporary elegance.

The moon phase model is equipped with the Cal. Elite 692 movement, which, despite its ultra-thin design, has a power reserve of approximately 50 hours and an automatic winding mechanism.

Recommended Moon Phase Models

Let's take a look at the moon phase models that each company boasts, including Breguet, IWC, and Zenith.

Breguet Classique 7787

Breguet's "Classique" is the brand's signature collection. The dial, hands, and case are all embodied in a simple beauty that has been polished to the utmost, and its supreme expression reigns supreme in the watch world. This coveted collection allows you to fully enjoy the unique design of Breguet, the father of watchmaking, with Breguet hands, Breguet numerals, oven-fired enamel dials, and guilloché engraving. The "Classique 7787" in particular is truly beautiful, with its playful dial design and the exquisite placement of the moon phase at 12 o'clock.

The deep brown strap and rose gold bezel harmonize perfectly, making this a watch that I would recommend to anyone looking for a simple yet stylish watch.

IWC Portugieser Perpetual Calendar

The Portugieser is IWC's classic line, a collection characterized by its elegant and refined design.

The Portugieser Perpetual Calendar is a moon phase watch with an 18K red gold case and a dark brown alligator strap by Santoni. The sapphire crystal crystal is arched using advanced techniques, and the beauty of its edges is breathtaking.

The perpetual calendar, which is equipped with a perpetual moon phase, is a calendar function that does not require adjustment for leap years. When you pick it up and put it on your wrist, you can feel the presence of the weighty mechanism, and it is a blissful watch that allows you to enjoy what it means to be an extremely complicated watch.

Zenith Elite Moonphase

This slim and elegant Elite collection features a moon phase display at 6 o'clock, showcasing the gold moon and stars driven by an intricate mechanism, and a small seconds hand at 9 o'clock.

The sunray-patterned dial shows different expressions depending on the angle and the amount of light, and the satin-finished star-shaped rotor weight can be seen through the see-through caseback.

The moon phase's colors evoke the solemnity of the night sky and are extremely elegant, expressing on the dial the mysterious charm of the moon as it stands out against the veil of night.

Omega "Speedmaster Moonphase"

Omega's Speedmaster, commonly known as the "Moonwatch," is also a collection that suits the moon phase well.

The most distinctive feature of this model is the moon phase display featuring a realistic moon at the 6 o'clock position. It is a multi-functional model with a coaxial hour and minute counter at the 3 o'clock position and a small second and pointer date at the 9 o'clock position. Furthermore, the dial is decorated with meteorite.

The movement is equipped with a coaxial escapement and is certified as a Master Chronometer by METAS. It boasts ultra-magnetic resistance of 15,000 gauss and excellent portability, making it an extremely practical watch.

Blancpain Bathyscaphe Complete Calendar Moon Phase

The designs of moon phase discs vary by brand, but if you want to enjoy a watch with a "face," Blancpain is a good choice.

Blancpain is a brand founded by Jean-Jacques Blancpain in Villeret, Switzerland in 1735. Over its long history, the brand has demonstrated a strong presence in the watch market, releasing the Rolls in 1926, the world's first ladies' watch equipped with an automatic movement, and in 1953 creating the Fifty Fathoms, the ancestor of the modern diver's watch.

This time, we're looking at the Bathyscaphe Complete Calendar Moon Phase. This collection, which traces its roots back to the 1956 Blancpain-created diver's watch of the same name for daily use, is currently available in a variety of variations. This model is a ceramic model released in 2024. It features the Bathyscaphe Complete Calendar Moon Phase's signature pointer date, small apertures for the day and month, and a moon phase at 6 o'clock, featuring a moon face surrounded by stars. This iconic face is sure to catch your eye.

Orient Star "M45 F7 Mechanical Moon Phase"

In 2025, Orient Star developed a new manual-winding movement with a new moon phase display. The latest model equipped with this movement is the M45 F7 Mechanical Moon Phase.

While previous models also had moon phase displays, this model's key feature was its pursuit of luxury. The moon phase display has been redesigned from the traditional one-piece structure to a three-layer structure consisting of a disc, a mother-of-pearl moon, and a lunar phase wheel. This was apparently done in order to achieve a more precise expression. The clearance between the dial and the hands has also been reduced, and combined with the minimalist two-hand display mechanism, it has been finished as a classic, high-end moon phase.

On the other hand, the selling price is 418,000 yen including tax, making it an affordable price, so it is also recommended for users who are considering purchasing a moon phase watch for the first time.

Longines "Flagship Heritage"

This is a reproduction of the "Flagship" model that Longines released in 1957. The three-hand model has long been a best-seller in the lineup, but in 2023 a model with a moon phase was added. It is coaxial with the pointer date, making it highly practical.

The silver opaline colored domed dial and gold colored hands and indexes create a warm feeling. The movement is equipped with a silicon balance spring and has a power reserve of approximately 72 hours.

IWC Portofino

Let's take a look at another moon phase model from IWC, this one from the Portofino collection, known for its timeless and unpretentious design.

This model retains the collection's iconic design elements, such as the rounded case lines and long leaf-shaped hour and minute hands, and is equipped with a moon phase display at the 12 o'clock position.

The case, with its polished finish, is elegant, and combined with the moon phase, it will add a special accent to any outfit.

How to adjust the moon phase mechanism

If the error in the moon phase display becomes too large, you will need to adjust it yourself. There are two ways to adjust it.

Turn the crown

The moon phase is adjusted by turning the crown. You can easily check the age of the moon for any day by searching the internet for a moon phase calendar.

The basic specifications for the type that adjusts with the crown are to first set the moon phase to the new moon, which is the moon age of 0, and then turn the crown the number of days that have passed since the most recent moon age of 0. The same procedure can be used to adjust the moon phase based on the full moon, which is 15 days old.

The crown is used not only to adjust the moon phase, but also to adjust the date and time, so be sure to check the instruction manual for instructions on how to set them.

Press the push button

Some models have a push-button that allows you to adjust the moon phase, while most models have a small push-button on the side of the case.

The basic concept of adjusting the pusher is the same as adjusting the crown: check the age of the moon on the lunar calendar, set the moon phase to 0, and then use the pusher to advance the number of days that have passed since the most recent new moon or full moon.

The pushers are sometimes used to adjust the chronograph, so be careful when operating them. On some models, the small adjustment buttons are called "correctors."

Enjoy the mysterious and fascinating mechanism of this complicated mechanism

The moon phase, which shows the waxing and waning of the moon on the dial, is a complication with a strong decorative significance, and today each brand produces its own unique moon phase model.

When choosing a moon phase watch, it's important to consider the characteristics of the brand and collection. Pick up a romantic moon phase model and experience the microcosm on your wrist.