Presenting the grey edition Citizen 'Tsuki-yomi' Radio-Controlled Moon Phase, the worlds first light-powered radio-controlled moon phase movement. In celebration of the 30th anniversary of the first Citizen radio-controlled watch, the brand are debuting the worlds first fully analogue moon phase function for light-powered watches. The Tsuki-yomi collection (which translates toreading the moon) has a new radio-controlled Eco-Drive Cal. H874 movement that provides ±15 seconds accuracy per month, a revolutionary proprietary Super Titanium case and bracelet, and artfully crafted moon pattern dials. The watch calculates the phase of the moon each day by using signals received from multi-band radio transmitters combined with a unique mathematical formula developed by Citizen calledLuna Program. The phase of the moon is then automatically adjusted and displayed at the six oclock position. Sustainably powered by any light, including moon light, with our proprietary Eco-Drive techno