Sure, the latest Apple Watch Series 9 is packed with pretty cool features, but what about a watch that dates back to Ancient Greece?
If you're a history buff, you've probably heard of the Moon Phase watch. It's one of the oldest complications ever discovered in the history of horology. Today, this ancient timepiece has transformed into something truly one-of-a-kind.
Here's everything you need to know about these night sky-inspired watches.
What is a Moon Phase Watch?
A Moon Phase watch or complication is a timepiece that shows the many different phases of the Moon on its dial. For most models, that's typically over the entire 29.5-day lunar cycle. This feature is called a Moon Phase complication since it's not directly related to telling time.
The Moon Phase dial shows the lit portion of the Moon as it orbits the Earth. Most Moon Phase watches display the current phase of the Moon, often hiding the parts that aren't sunlit. Like any other watch, designs can vary between different models.
History of Moon Phase Watches
The history of Moon Phase watches starts in Ancient Greece with the Antikythera mechanism. It was the earliest known mechanical device used to predict celestial events like Moon phases and eclipses.
For about 2000 years, nothing matched the complexity of these clocks until astronomical clocks were invented in the Renaissance. These were often found in churches and gave a geocentric view of the universe. Even as Earth-centric beliefs faded, the Moon Phase complication endured.
It appeared in standalone clocks in the 16th century, then in pocket watches, and eventually wristwatches by the 20th century. Of course, lunar-inspired timekeeping is no longer essential, but the Moon Phase complication is still a cool feature to have. Any watch with this feature is called a Moon Phase watch.
How Does a Moon Phase Watch Work?
A Moon Phase watch can be powered by different movements. For example, quartz watches are battery-powered and accurately programmed. Meanwhile, mechanical and automatic models require winding or movement to function.
In a Moon Phase automatic watch, a set of gears tracks the Moon's position. Behind the dial is a disc with two Moons, rotating every 29.5 days, mimicking the lunar cycle.
A 59-tooth gear moves the disc slightly every 24 hours, making the Moons look like they're moving. There are actually two Moons, so one can appear in the aperture after each lunar cycle.
The aperture, shaped like a semicircle with bumps on the sides, represents the Earth's silhouette. When it's set correctly, the watch tracks the Moon's phases as it appears and disappears. This way, you'll know whether it's waxing or waning.
Accuracy of a Moon Phase Watch
Most Moon Phase watches lose their accuracy after about three years. That's because they're designed with a 59-tooth gear, which estimates the lunar cycle to 29.5 days. However, the actual cycle is slightly longer, at 29.530588853 days.
This small gap can make a huge difference – the watch will lose a day of accuracy every three years. If that's too high-maintenance for you, look for a Moon Phase watch with a 135-tooth gear. These are a lot more precise and only need to be adjusted every 122 years.
Bosom Moon Phase Watch vs. Radial Moon Phase Watch
You may prefer a classic wind-up mechanical watch, a pocket watch, or one with a battery-operated quartz movement. But what really matters is the Moon Phase display – did you know there were two types? Bosom and radial.
The bosom Moon Phase watch has a crescent-shaped aperture with two bumps on the sides. This aperture represents the Earth's silhouette.
Meanwhile, the radial display has a hand pointing to the shape of the Moon. This way, the Moon position indicators will be the moving parts, not the pictures of the Moon.
5 Best Moon Phase Watches
We did some testing and found the top 5 Moon Phase watches in the market today. Here are our top picks.
Rolex Cellini Moon Phase
The Rolex Cellini Moon Phase watch is the perfect example of an elegant dress timepiece. While Rolex is known for its versatile sports watches for casual settings, the Cellini Moon Phase is an underappreciated gem.
Unlike most watches from the brand, this gold Moon Phase watch doesn't have an Oyster case. It's also the only model in the Rolex lineup featuring a Moon Phase dial! Positioned at 6 o'clock, the striking blue Moon Phase display is the perfect contrast against the pristine white dial.
Pros
- Luxurious design
- Perfectly proportioned at 39mm.
- Detailed dial
- Accurate for 122 years
Cons
- Costs a fortune
Omega Speedmaster Moon Phase
Any list of Moon Phase watches would be incomplete without the Omega Speedmaster: the watch that visited the Moon six times!
But there's more to this watch than just its lunar heritage. We really loved the hyper-realistic depiction of the Moon on the dial, nestled behind a crescent aperture at 6 o'clock. Every detail, including a footprint for the first Moon landing, is stunningly precise.
Plus, this watch is made from robust stainless steel and only needs manual adjustment only once every decade.
Pros
- Impressive resistance to magnetism
- Stylish build
- Vintage Moon Phase watch
- Impressive rate stability
Cons
- Hard to wind
Patek Philippe Nautilus 5712 Moon Phase
Patek Philippe is one of the top watch brands and their moonphase watch lives up to the expectations.
The Moon Phase subdial is the main complication on the Patek Philippe Nautilus 5712's dial, but it's still pretty subtle inside the date subdial. Combining these two dials was the perfect way to declutter the Nautilus' iconic embossed face.
There's also a discreet indicator for the 48-hour power reserve of its self-winding movement. Lastly, the gradient blue dial perfectly complements its stainless steel case, and we really love how lightweight it is.
The only issue is that it's definitely larger than the 44mm it's advertised to be, so it's a pretty big Moon Phase watch.
Pros
- Highly comfortable
- Lightweight build
- Incredible design
- Best affordable Moon Phase watch
Cons
- Subpar micro-rotor movement
Cartier Drive Moon Phase
Moon Phase watches typically come in traditional designs, but that's not true for the Cartier Drive Moon Phase. This Cartier creation has a unique charm, all thanks to its rounded hexagonal shape.
The bold Roman numerals caught our attention first, followed by the Moon Phase aperture at 6 o'clock. The striking shades of blue and yellow in these Starry Night watches are the perfect contrast against the silvered guilloche dial. The Moon is peeking through a set of white clouds and golden stars – could this watch get any better?
The Moon Phase dial is the only extra feature, so it takes centre stage on the face of the watch. The signature Cartier blued steel hands are also perfect for the celestial theme.
Pros
- Beautiful case shape
- Clean dial
- Reliable and long-lasting
Cons
- Small crown
- Expensive
Jaeger-Lecoultre Master Calendar
If you're a fan of Lunar calendar watches, this one will definitely catch your eye. The Jaeger-LeCoultre Master Calendar is all things timeless and sophisticated. Its calendar feature, wrapped around the Moon Phase dial, tells you exactly how far you are from a full Moon.
The unique jumping date function makes sure view of the Moon Phase ouis never interrupted. Plus, it's made with robust stainless, and you'll hardly ever need to manually adjust it.
Pros
- Great investment
- Beautiful and classic design
- Ideal for the old-fashioned
- Triple-calendar Moon Phase watch
Cons
- A little hard to see the hands
How to Set a Moon Phase Watch
So, you've finally found the Moon Phase watch of your dreams – it's time to set it up. Follow these steps for an accurate Moon Phase watch setting.
- Before adjusting your Moon Phase watch, carefully pull out its crown and position the hands at 6:30. This will prevent potential damage to the movement while setting the Moon phase.
- Next, look up the current appearance of the Moon from Earth on Google. You'll also need to find out whether the Moon is waxing or waning.
- Once you've identified the Moon's phase, adjust the disc so that the Full Moon is visible at the centre of the window. This position indicates that the Moon is at its fullest phase.
- Then, calculate the number of days since the last Full Moon. Use the crown to advance the Moon to the current phase – one notch adjustment for each day.
- Finally, push the crown back to its normal position, and your Moon Phase watch will be set.
Of course, you want to be able to read your Moon Phase watch, too.
Just look at the small dial on the watch face – that indicates the current phase of the Moon. The display shows the different Moon phases, such as waning crescent, gibbous, full, etc. Align the position of the Moon on the dial with the current date to determine the Moon phase.
Takeaway
Moon Phase watches are more than just unique and stylish accessories – they're a journey through time, dating back to Ancient Greece. Even in the modern era, they've visited the Moon and keep wearers up to date with the lunar calendar.
