Radio Controlled Moonphase BY1018-80X Watch

The Watch

Founded in 1918, Citizen is a Japanese watchmaking brand that has carved out a leading position in the industry through remarkable innovation. Its models stand out for their reliability, robustness, and compelling design. To celebrate the 30th anniversary of its first radio-controlled watch, the brand launches the Radio Controlled Moonphase BY1018-80X from the Tsuki-yomi collection - the Japanese name for the god of the moon. This model is distinguished by the world's first fully analog moonphase function for a light-powered watch. The watch comes with a round case in titanium, lightweight and durable, with a refined silver finish. It is topped by a fixed bezel with DLC coating in matte black, providing an elegant contrast to the case's clean design. The case measures 43 mm in diameter and 10.87 mm thick, making it a bold presence on men's wrists. It is protected by a flat sapphire crystal, offering excellent resistance to scratches and damage. On the right side, a knurled crown measuring 6.00 mm in diameter allows easy adjustment of hours, minutes, and date. Flanking it are the two pump push-buttons for operating the watch's various complications. The caseback is a pleasure to behold, featuring a world time scale with the names of major global capitals. Snap-fitted and crafted in titanium, it ensures water resistance to 10 ATM.

The Dial

The dial of this watch delivers an engaging reading experience. Striking and atmospheric, it is designed to evoke the surface of the moon. It features a red base framed by a black ring marked with a minute track, accompanied by beveled baton indices in silver. These markers share the same luminescent material as the pointed hands, ensuring clear legibility in low light. The matte silver seconds hand is shaped like a sword, its counterweight evoking a three-pointed hilt. Beyond hours, minutes, and seconds, the dial also displays the date in a white-framed window at 4 o'clock. A sub-dial at 12 o'clock shows the day, along with a power reserve indicator and a northern/southern hemisphere display. The dial also features a highly accurate radio-controlled time function, synchronized with an atomic clock to within ±1 second. It includes a day/night AM/PM indicator and a sub-dial at 6 o'clock dedicated to a beautifully illustrated moonphase complication. This feature offers ultra-precise readings that can switch between hemispheres for geographic accuracy. It is based on a unique mathematical formula developed by Citizen called the "Luna Program," through which the watch calculates the moon's daily phase from signals received via multi-band radio transmitters. The finishing touch is the brand signature at 3 o'clock, alongside the movement name and collection name.

The Movement

This model is powered by an Eco-Drive H874-08M quartz movement. This reliable caliber achieves a precision of ±15 seconds per month, thanks to radio-controlled atomic timekeeping technology. It supports the following functions: hours, minutes, seconds, radio control, perpetual calendar, world time, date, day, moonphase, second time zone, and 24-hour display.

The Strap

The bracelet supporting this watch is an elegant complement that enhances the beauty of the model. Crafted in titanium, it features a three-row link construction with a refined brushed finish accented by two polished lines. This bracelet delivers exceptional wrist comfort and measures 22 mm wide at the lug, tapering to 20 mm at the push-button deployment clasp.

Water Resistance

With water resistance to 100 meters - or 10 ATM in watchmaking terms - this bold timepiece is equally at home at a gala or in the water. Feel free to wear it in the shower, the bath, or during a vigorous swim. That said, our team of watchmaking experts wants to be clear: this model is not designed for scuba diving, freediving, or use with high-pressure cleaning equipment. Remember: showers, baths, and swimming only - and keep the crown and push-buttons dry while submerged.