The Citizen Tsuki-yomi A-T makes moonphases actually feel important
Buffy AcaciaWho needs to know the phases of the moon? Astronomers? Astrologers? Well, while it might not be important to most watch nerds, there are plenty of real reasons why the lunar phase is important. There are fishing and farming operations which still take the moon’s guidance into account while monitoring harvests and the tides, and it can also play a key role in various spiritual practices. That said, these people don’t generally need a watch with a moonphase display. Even if they did have one, they will never be the most accurate of complications. A movement can guarantee as much accuracy as it likes, but actually setting or reading the tiny moon in a crescent window is guesswork at best. The Citizen Tsuki-yomi A-T redefines the need of moonphase watches by introducing atomic clock synchronisation and clear, crisp displays.
The case
It goes without saying that Citizen are a huge brand with countless product lines, and each of them cater to different audiences. Those angled towards watch enthusiasts tend to have smaller case sizes, while more general consumer ranges creep up in size. It’s hard to imagine a buyer for the Citizen Tsuki-yomi A-T who isn’t obsessive about detail, but Citizen have covered their bases by ensuring a large-diameter case with tricks for easy wearability. The 43mm diameter is essential for the dial’s breathing room, but the short lugs are 48mm from tip-to-tip which will comfortably suit an average wrist. The use of titanium cuts down on the weight as well, with a total weight of 98 grams, or approximately two thirds of an average dive watch.
Not only does the titanium help make the watch easier to wear, but it also contributes a darker hue to the metal. Between the alternating brushed and polished surfaces, various tones of grey are brought out which also shift with the light. The generous curves and neatly-clipped angles of the case design lend themselves to a sporty wearing experience, but the polished bezel and bracelet components ensure enough sparkle to be versatile. At only 11mm thick, it’s surprisingly elegant for the diameter too.
The dial
Despite being a watch which is absolutely purpose-driven, the Citizen Tsuki-yomi A-T isn’t short on beauty. Instantly, the eye is pulled in by a depiction of the Moon’s cratered surface beneath a translucent blue sapphire layer, but there are also versions available with a red or grey tint. The second place your eye travels to is the large moonphase display at 6 o’clock, placed at the top of a guilloché subdial surrounded by directions for north and south. This is definitely one of the largest moonphase displays I’ve seen on a watch, and the bright white Moon shines out against a black backdrop with no stars for distraction. Unfortunately our photos didn’t capture the Moon, but it is much easier to read the phases than on most others.
Other details are well-appointed on the dial, with clinically sharp applied indices and hands. The subdial at 12 o’clock is a multi-function indicator that can point to the weekdays, indicate hemispheres, or give you a power reserve reading depending on the crown setting. There’s a day/night indicator with a 24-hour hand at 9 o’clock, and a traditional date window placed at 4. Other technical functions can be read with the Tsuki-yomi’s chapter ring, such as time zones, daylight savings, and the current status of its link to atomic clocks. Of course, not every region receives radio signals for atomic synchronisation, so be sure to look it up in your area before purchasing.
The movement
Powering the Tsuki-yomi A-T is the calibre H874. It’s an Eco-Drive movement, which means that the translucent dial actually has solar charging cells underneath it. The solar capability eliminates the need for battery changes, and it can also be charged with low, ambient light if you don’t live in a sunny climate. Atomic timing is definitely one of the main draws for this watch, but if you fall in love with its design and function outside of an atomic radio zone then the +/-15 seconds per month accuracy should serve you fine. If you’re not someone who wears the same watch every day then you can rest easy with a power reserve of 30 months on a full charge, however Citizen recommend at least 5 hours of sun or fluorescent light per week for optimal performance.
The bracelet
Titanium watches are usually palmed-off with rubber straps to save the hassle of machining a titanium bracelet, however Citizen have gone to the effort. There’s nothing revolutionary about its design, with a pretty standard three-link arrangement, but the polished edges of the centre links add just enough sophistication to keep things interesting. If you’re interested in finding aftermarket straps in leather or otherwise, the 22mm lug width opens up plenty of exciting options. The folding clasp is possibly the only component which could have been improved, as it doesn’t offer much micro-adjustment and the clasp itself is not very thick. That said, it does the job and doesn’t take much away from the wearing experience of an otherwise high-quality watch.
The verdict
There seems to be a latent connection between watch enthusiasts and the Moon, whether it’s something to do with landing on it or just staring at it. In creating the first atomic-synchronised moonphase watch, the Citizen Tsuki-yomi A-T will definitely capture a lot of imaginations purely based on the dial. It’s doubtful that such accurate knowledge of the lunar cycle will actively benefit the owners of the watch, but it’s enough of a novelty to draw in admirers from any crowd.
Citizen Tsuki-yomi A-T pricing and availability
The Citizen Tsuki-yomi A-T is now available from Citizen’s website and retailers. Price: US$850
| Brand | Citizen |
| Model | Tsuki-yomi A-T |
| Case Dimensions | 43mm (D) x 11mm (T) x 48mm (L2L) |
| Case Material | Titanium |
| Water Resistance | 100 metres |
| Crystal | Sapphire |
| Dial | Blue, red, or grey translucent sapphire |
| Lug Width | 22mm |
| Strap(s) | Titanium bracelet |
| Movement | Eco-Drive calibre H874 |
| Power Reserve | 30 months |
| Functions | Hours, minutes, seconds, day/night indicator, weekday, date, moonphase, power reserve, radio control to atomic clock, world time |
| Availability | Available now |
| Price | US$850 |