How to Set a Moonphase Watch

The moonphase watch is one of the most aesthetically pleasing complications in watchmaking. As the name suggests, the moonphase watch keeps track of the moon’s many phases as they change over its lunar cycle.

This article will discuss everything you need to know about moon phase watches, their accuracy, and how to set them up. 

If you’re interested to learn more about it, keep reading!

What is a Moon Phase Watch?

As stated above, a moon phase watch is a timepiece that keeps track of the moon’s phases. Through its mechanism, the watch can display the progression of the lunar cycle, which lasts 29 days, 12 hours, and 44 minutes.

Most watch brands consider a lunar cycle to be 29.5 days long because of gearing. If you’ve seen a standard moonphase disc, you’ll know it has two moons rather than just one. 

One of these two moons always covers the aperture that allows for reading the moon’s phase. On the other hand, it always moves at the same speed and is prepared to take over when the other moon begins to fade, and it is time for the new moon to rise.

2 Types of Moon Phase Complications

Moonphase watches can be divided into two categories: bosom and radial

The most popular type of moonphase watch is the “bosom,” which uses a graphic method to visually display the moon in all its phases inside a crescent-shaped aperture. 

In contrast, the other type of moonphase watch is the “radial,” which tracks the lunar cycle using an indicator hand.

So, How Does a Moonphase Watch Work?

Moonphase complications, one of the oldest watch movements ever created, mainly require positioning two similar moons on a disc beneath the dial. A 59-tooth drive wheel that controls the disc’s movement moves the disc once every day using a mechanical finger. 

After completing a single 29.5-day lunar cycle, the second moon appears in the aperture, resulting in 59 teeth (29.5 x 2). The dial and aperture designs will affect the intricacies of the underlying moon disc, but the driving wheel will always be the same.

The majority of moonphase watches are dependably precise. However, the 59-tooth driving wheels’ accuracy is also slightly limited.

As a result, conventional moonphase watches will be off by a full day once every two years, seven and a half months, implying that you’ll need to manually set the timepiece once every three years if you want to keep up with the lunar cycle properly.

In the meantime, some high-end manufacturers use a 135-tooth driving wheel to improve accuracy significantly. After 122 years, the watches will be off by one day compared to two years, seven and a half months, which is a significant difference.

How to Set a Moon Phase Watch [3 Steps]

how to set a moonphase watch

Although it’s simple enough, setting a moon phase watch can be more challenging than setting the time.

This process can be time-consuming for some watches, but the good news is that you only need to complete it every two and a half years. It’s a fair exchange for such a complex mechanism.

Here is a brief general description of the procedure you should follow when setting up a moon phase watch (Please note that the exact steps may vary depending on your timepiece.):

1. Know the Phases of the Moon

First, determine the current phase of the moon. You can easily do this via the internet. Once you have identified the current moon phase and know whether it’s waxing (no moon to full moon) or waning (full moon to no moon), you can start setting the moon phase on the dial.

2. Set the Moon Phase

Next, set the watch to 6:30 as a safety measure to ensure you don’t harm any of the complication’s mechanisms. As you can see, the moon advances somewhat with each touch of the corrector on the case side to adjust the moon phase.

Since it is easy to identify the new moon and full moon phases on the aperture, we advise noting the number of days that have passed since the last one. \

Let’s assume that eight days have passed since the last full moon. Click the corrector seven more times to adjust for seven days after advancing the moon phase until it is complete.

3. Set the Date

Next, put the date on the watch one day behind. Set the time, and go through one full day to reach the correct date. 

On the watch, note how the date changes at exactly midnight, yet the moon phase doesn’t change until just after one in the morning. Now, the date is correct, as is the AM/PM time and moon phase.

Best Moonphase Watches

moonphase watch
Source: Junghans

Junghans Meister Kalender Moon Phase Watch

The Junghans Meister Kalendar Moon is the ideal illustration of a contemporary presentation of a very traditional idea. They used a set of complications generally found on watches with more conventional leanings and 20th-century watch features, but they accomplished it with a refined, contemporary touch.

The Meister Kalendar Moon’s hour and minute hands are made of polished steel dauphine. Moreover, it has a classic design that draws inspiration from some of the watch’s more retro features. Meanwhile, a long, shiny steel stick serves as the second hand.

The watch also comes with a 21-mm brown leather strap, a dark chocolate brown with polished edges and a slight taper. It has a very level and even surface, thanks to the leather’s correction, which gives it a formal aspect. It has a satisfying firmness, is quite comfortable, and has an appealingly compact profile.

moonphase watch
Source: Omega

Omega Speedmaster Moonphase Master Co-Axial

The Omega Speedmaster Moonwatch’s most talked-about feature is the exceptionally high-resolution moon phase disc, which features an ultra-high-definition and accurate lunar surface.

A 44.25-mm broad casing is included with the watch. The sandwich-style case design is also relatively thick at 16 mm, and the bezel, case middle, and case back have varied widths. Despite its size, it is often comfortable and attractive when worn on the wrist.

Moreover, the case boasts a scratch-resistant sapphire crystal with anti-reflective treatment on both ends and is water-resistant to 100 meters. A transparent case back reveals the stunning in-house caliber within.

The bezel has a Liquidmetal tachymeter scale and is composed of a highly scratch-resistant satin-finished ceramic material. You can see a sophisticated and harmonious combination of polished and satin finishing on the beveled edges of the watch case from the side profile, as well as a glossy finish underneath the bezel.

Patek Philippe Nautilus 5726/1A 

The Patek Philippe Nautilus 5726/1A-014 boasts all the defining features of a Nautilus, such as the slightly rounded octagonal case, blue dial with horizontal embossing, white gold baton applied indexes and polished and satin-finished steel band.

Additionally, the dial is tidy, evenly distributed, and primarily divided into two portions. The 24-hour register is located in the lower half, surrounded by the white-gold moon phase disk and has a vast date window at the bottom. 

The top one has two small rectangular windows that indicate the month and day of the week, respectively, next to the double hour marker at twelve. Meanwhile, the dial of the Patek Philippe Nautilus 5726/1A-014 is symmetrical along the vertical axis that runs from the hour markers at twelve and six.

Are Moon Phase Watches Accurate?

We’ve explained that moonphase watches are unreliable, and anyone who has ever had one would agree.

Every month, a moonphase watch is off by an average of 44 minutes. That equates to 8 hours 48 minutes, or over nine hours yearly. So, what is the catch? Who would want them, anyway?

Even the best watch brands occasionally have trouble perfecting the moonphase indicator, which is one of the watch’s most sensitive and complicated systems. So, why do people still love them?

To start with, they are stunning. The moon phase display is so unique that it will draw admiring friends and coworkers’ attention. Both radial and bosom moonphase watches have beautiful aesthetics. 

They are beautiful, and the fine details give the design a further layer of complexity and refinement. On top of that, they constantly remind us of the celestial body that controls our moods and tides.

Finally, a wearer daily doesn’t care about this error. Set your watch back in with just a few minutes now and then.

The Bottom line

We hope we have guided you on how to set up a moonphase watch. Are moon phase watches suitable for everyone? Absolutely not. The moon tracking feature on a timepiece is only handy for some males, and they can be pricey.

However, the uniqueness and complexity of the issue are what give moon phases their magic, so it is safe to say they will be around for a while. 

Moonphase watches are fantastic timepieces with a lengthy history. They are quite attractive since they are both intricate and lovely. They may not be the most accurate if they are absurdly pricey, but do you care if you save a few minutes every so often? 

If you liked this article, check out our other reviews at

Other related articles: