Watches

Citizen Launches the Tsuki-Yomi A-T Timepiece

WatchesSep 26, 2023

Citizen Launches the Tsuki-Yomi A-T Timepiece

According to the watchmaker, it features the first light-powered atomic timekeeping moon phase movement.

Citizen Tsuki-yomi A-T moon phase watch
Comprising three models, Citizen’s new “Tsuki-yomi A-T” collection utilizes the “Luna Program” unique mathematical formula to calculate moon phase via signals from multi-band radio transmitters.
New York—Thirty years ago, Citizen launched its first atomic timekeeping watch. 

To celebrate, the watchmaker has just released three new models that feature what it says is the market’s first fully analog moon phase movement for light-powered watches. 

They’re called the “Tsuki-yomi A-T” collection, which translates to “reading the moon” and reference the ancient Japanese moon god, Citizen said. 

Each model has the Eco-Drive Cal. H874 movement. The watch calculates the phase of the moon each day by receiving signals from multi-band radio transmitters, a process that relies on a mathematical formula Citizen has developed called “Luna Program.” 

A window at the six o’clock position displays the moon phase, automatically adjusting it per the signals the watch receives.  

 Related stories will be right here … 

The technology also enables a “North-South” shift, meaning the display changes to match the moon phase view depending on if the wearer is in the Northern or Southern hemisphere. 

The Tuski-yomi A-T requires no manual adjustment for the moon phase. 

The watches feature Citizen’s “Super Titanium,” meaning titanium that is processed via the company’s proprietary surface-hardening technology called Duractect to create a scratch-resistant surface that is five times harder and 40 percent lighter than stainless steel. 
 
Citizen Tsuki-yomi A-T moon phase watch
The three models of the new Tsuki-yomi A-T collection feature a blue, silver, or magenta moon as the dial.


Each model has a Super Titanium 43 mm case and bracelet. 

Ref. BY1010-57L has a deep blue dial, Ref. BY1010-57H has a silver dial, and Ref. BY1018-55X has a “blood moon” or magenta dial and black Duractect DCL bezel. 

The new Eco-Drive Cal. H874 offers world time, perpetual calendar technology and 100 meters of water resistance. 

Available now, each model is priced at $850.   

The Latest

Movado Connect 2.0 watches
FinancialsNov 26, 2025
Movado CEO Talks Tariffs, Growing Interest in Accessible Luxury Watches

During its Q3 call, CEO Efraim Grinberg discussed the deal to lower tariffs on Swiss-made watches, watch market trends, and more.

Rosior Pumpkin Ring
TrendsNov 26, 2025
Piece of the Week: Rosior’s Pumpkin Ring

Rosior’s high jewelry cocktail ring with orange sapphires and green diamonds is the perfect Thanksgiving accessory.

Greenwich St. Jewelers Embrace Your True Colors Holiday Campaign
IndependentsNov 26, 2025
Greenwich St. Jewelers Launches Colorful Holiday Campaign

The “Embrace Your True Colors” campaign features jewels with a vibrant color palette and poetry by Grammy-nominated artist Aja Monet.

Recipients Collage 2025 - NJ (1872 x 1050 px) (1872 x 1052 px).png
Brought to you by
Impacting Tomorrow Today

How Jewelers of America’s 20 Under 40 are leading to ensure a brighter future for the jewelry industry.

Alejandro Cuellar
MajorsNov 26, 2025
Serafino Consoli Names New VP of Sales, Brand Development for the Americas

Luxury veteran Alejandro Cuellar has stepped into the role at the Italian fine jewelry brand.

Weekly QuizNov 20, 2025
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Grandview Klein scholarships
Events & AwardsNov 26, 2025
Grandview Klein Presents 4 Scholarships in Namibia

The company gave awards to four students at the Namibia University of Science & Technology, including one who is a Grandview Klein employee.

Margaret “Maggie” Hoisik
IndependentsNov 25, 2025
Pearl Stringer Margaret Hoisik Dies

She is remembered as an artist who loved her craft and was devoted to her faith, her friends, and her family.

roseco-catalog.png
Brought to you by
Roseco Releases New Full-Line Catalog

Roseco’s 704-page catalog showcases new lab-grown diamonds, findings, tools & more—available in print or interactive digital editions.

Finestar manufacturing
SourcingNov 25, 2025
Finestar Opens Diamond Manufacturing Facility in Johannesburg

It joins the company’s other manufacturing facilities globally, including in India, Botswana, and Namibia.

State Property Toadstool Pendant
TrendsNov 25, 2025
Amanda’s Style File: Polka Dots

The polka dot pattern transcends time and has re-emerged as a trend in jewelry through round-shaped gemstones.

Stock image of gavel and books
CrimeNov 25, 2025
Former Arizona AG Official Charged With Trafficking Stolen Jewelry

Vanessa Hickman, 49, allegedly sold a diamond bracelet that was mistakenly sent to her home.

GIA executives John Koivula, Kathryn Kimmel, Susan Jacques, Tom Moses, Alice Keller, James E. Shigley
Events & AwardsNov 25, 2025
GIA Awards Susan Jacques With Its Highest Honor

GIA’s former president and CEO was presented with the Richard T. Liddicoat Award for Distinguished Achievement.

20251124_MNQ social media etiquette header.jpg
Recorded WebinarsNov 24, 2025
Watch: Top Tips for Social Media Etiquette

Social media experts spoke about protecting brand reputation through behaving mindfully online.

Cynthia Erivo in Muse’s Have a Heart x Cynthia Erivo Collection
CollectionsNov 24, 2025
Muse Debuts a Wicked 'Have a Heart x Cynthia Erivo' Sequel

The second drop, which includes more Elphaba-inspired pieces from additional designers, will continue to benefit nonprofit Dreams of Hope.

J.R. Dunn Jewelers employees
IndependentsNov 24, 2025
J.R. Dunn Jewelers Names New President

Second-generation jeweler Sean Dunn has taken on the role.

Amber Pepper
MajorsNov 21, 2025
Natural Diamond Council Names New CEO

Amber Pepper’s main focus will be on digital innovation and engaging younger consumers.

Origin De Beers Group logo
SourcingNov 21, 2025
De Beers’ Branded, Traceable Diamonds Roll Out to 19 Retailers

Called “Origin by De Beers Group,” the loose, polished diamonds are being sold in a total of 30 stores in the United States and Canada.

Melissa Kaye Rocky Infinity Emerald Necklace
CollectionsNov 21, 2025
Piece of the Week: Melissa Kaye’s ‘Rocky Infinity’ Necklace

The lariat necklace features a 4.88-carat oval-cut Zambian emerald in 18-karat yellow gold.

Phillips auction of The Vanderbilt Sapphire brooch
AuctionsNov 20, 2025
Vanderbilt Jewels Shine at Phillips Sale, Pink Diamond Withdrawn

A 43-carat sapphire brooch from the Vanderbilt collection was the top lot of the Geneva sale.

Rebecca Rau Jewels Green Flame Necklace
CollectionsNov 20, 2025
Rebecca Rau Jewels Debuts With ‘Then & Now’ Collection

Rau is a fourth-generation art and antique dealer from M.S. Rau gallery whose first jewelry collection merges artifacts with modern design.

Purvi Shah
Policies & IssuesNov 20, 2025
RJC Names New Executive Director

Former De Beers sustainability leader Purvi Shah will take over the role in February 2026.

Julia Griffith
GradingNov 20, 2025
Julia Griffith Joins SSEF as Head of Education

She previously taught at Gem-A and is the founder of The Gem Academy.

Helena Bonham Carter in Larkspur & Hawk Once Upon a Time Campaign
CollectionsNov 19, 2025
Larkspur & Hawk Celebrates 25 Years With Helena Bonham Carter Campaign

The British actress and her daughter modeled pieces from the brand’s new “Palette” capsule for its “Once Upon a Time” holiday campaign.

Google reviews on a phone screen and a laptop
TechnologyNov 19, 2025
Google Has a New Form for Reporting ‘Review Bombing’ Attacks

Plus, the tech giant shares the steps retailers should take if they believe they’re a victim of a review extortion scam.

Shaftel Diamonds logo and jeweler’s bench
IndependentsNov 19, 2025
Houston Jeweler Keith Shaftel Retires, Next Generation Steps In

Danny and Gaby Shaftel are now Shaftel Diamonds’ CEO and chief operating officer, respectively.

Midas chain mini studs
TrendsNov 19, 2025
Midas Chain Releases 2025 Holiday Style Guide

The jewelry manufacturer’s seasonal offering features its new “Melodie” bangles, as well as mini stud earrings and layering pieces.

Jewelry from NYC Jewelry Week 2024
Events & AwardsNov 18, 2025
NYC Jewelry Week 2025: 12 Must-See Events

With more than 140 activations taking place in New York City now through Nov. 23, these 12 events are can’t-miss moments.

×

This site uses cookies to give you the best online experience. By continuing to use & browse this site, we assume you agree to our Privacy Policy