This month, Citizen unveiled what they call the world’s first light-powered moon phase watch combined with atomic timekeeping.

The Tsuki-yomi A-T is presented in a 43 mm silver tone hardened titanium with a sapphire crystal, solid titanium caseback, and matching bracelet — and is offered in three different dial variations, all of which feature a moon pattern (light gray, blue, red).

Driven by Eco-Drive caliber H874, this quartz timepiece has an accuracy of -15/+15 seconds per month, thanks to radio-controlled atomic timekeeping technology, which Citizen first offered 30 years ago.

The watch displays the time, the day-date, the world time (24 time zones), AM/PM, and a perpetual calendar.

What’s most noteworthy though, is the advanced moon phase function that has the ability to do a North-South shift, which switches the moon phase display to match the view either from the Northern or Southern Hemisphere. Also, making the moon phase function ultra-precise is Citizen’s Proprietary “Luna Program,” which uses a unique mathematical formula that calculates the phase of the moon each day from signals received from multi-band radio transmitters.

The Tsuki-yomi A-T has 22 mm lugs, is 100 meters water-resistant, and can be powered by any light source.

Retail is $850.


Photo by Citizen.

Posted by:Jason Pitsch

Jason is the founder of Professional Watches and specializes in writing, product photography, and digital marketing.