Citizen BY1018-55X Super Titanium™ 'Tsuki-Yomi' Moon Phase Watch - W38380

Introducing the Citizen 'Tsuki-yomi' radio-controlled Moon Phase - the world's first light-powered radio-controlled moon phase movement. To celebrate the 30th anniversary of the first CITIZEN radio-controlled watch, Citizen are debuting the world's first fully analogue moon phase function for light-powered watches. The Tsuki-yomi collection (directly translating to “reading the moon”) features a new radio-controlled Eco-Drive Cal. H874 movement that provides ±15 seconds accuracy per month, revolutionary proprietary Super Titanium™ material and artfully crafted moon pattern dials. Based on a unique mathematical formula developed by CITIZEN called “Luna Program”, the watch calculates the phase of the moon each day from signals received from multi-band radio transmitters. The phase of the moon at the six o'clock position is then automatically adjusted and displayed. With a striking red pattern of the moon's surface on the dial paired with a black outer ring and date display at the 4 o'clock position, the watch boasts a 43mm case and is sustainably powered by any light, including moon light, with Citizen's proprietary Eco-Drive technology: this timepiece never needs a battery.