Citizen’s 2018 Caliber 0100 pocket watch was a one-off concept, not a watch customers could buy. It showcased an Eco-Drive movement that Citizen rated accurate to ±1 second per year, in a tribute to the company’s first pocket watch, released in 1924. Citizen’s current Caliber 0100 products are wristwatches, not this pocket-watch concept.
What was the Citizen Caliber 0100 pocket watch?
Citizen unveiled the Caliber 0100 movement at Baselworld in 2018, during its 100th-anniversary year. The pocket watch was a conceptualized design honoring the company’s first pocket watch, which Citizen says was released in 1924. Its announcement called the piece “Cal.0100 Concept Model (Not for sale).” Citizen’s announcement, dated March 22, 2018, described the concept as a tribute to the 1924 watch and the anniversary.
That distinction matters: the pocket watch demonstrated the movement and its technology, but it was not a retail model. Citizen’s current Caliber 0100 offerings are wristwatches with the same stated annual accuracy. They are related products, not versions of the concept pocket watch. Citizen’s current Caliber 0100 product information covers the wristwatch lineup.
How accurate is Caliber 0100?
Citizen specified accuracy of ±1 second per year for the Caliber 0100 movement. That is the manufacturer’s stated figure, not an independent test result for the concept pocket watch. Citizen also lists the same annual accuracy for current Caliber 0100 wristwatches.
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- From the Bulova Men's Classic Collection, inspired by vintage design, our classic watches achieve a tailored, understated look that's always in style.
- 3 Hand, Calendar
- Silver-Tone Stainless Steel with Curb Chain and Clasp to Detach
- Black Dial with Red Second Hand Accent, Mineral Crystal
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The movement is designed to keep time autonomously; Citizen says it does not depend on radio towers or GPS satellites to correct the time. That makes the claim different from the accuracy of a watch that regularly synchronizes to an external time signal. Citizen’s technical explanation describes its approach to precision timekeeping.
How does the Eco-Drive movement work?
Eco-Drive uses light to generate and store energy for the watch. It avoids regular battery replacement, but it does not run without stored energy: the movement draws on energy accumulated from light.
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- 【 VINTAGE AESTHETIC 】 Features a classic antique bronze finish with a transparent acrylic face. Elegant Roman numerals adorn both the outer bezel and inner dial, creating a timeless, distinguished look that pairs perfectly with suits, vests, and steampunk attire.
- 【 DURABLE & SAFE ACRYLIC 】 Say goodbye to fragile glass. The watch is built with high-strength acrylic for both the inner and outer lenses. This material is impact-resistant and shatterproof, making it a safer and more durable choice for everyday pocket watch use.
- 【 COMPACT & PORTABLE 】 Measuring approximately 4.6 cm (1.8 inches) in diameter, this pocket watch is perfectly sized for easy carrying. It won’t weigh down your pocket or bag, making it ideal for daily commutes or travel.
- 【 COMPLETE WITH CHAIN 】 Includes a matching 37 cm (14.5 inches) bronze-tone chain. The length is specifically designed to securely attach the watch to vest buttons, belt loops, or handbags, preventing loss while keeping it easily accessible.
- DUAL NUMERAL DISPLAY: The dial showcases Roman numerals alongside minute markers, offering a distinguished and easy-to-read classic look.
A higher-frequency quartz oscillator
Citizen says Caliber 0100 uses an 8.4 MHz AT-cut quartz oscillator—8,388,608 Hz—rather than the 32,768 Hz oscillator typical of conventional quartz watches. Citizen’s 2018 announcement says the higher frequency and the temperature correction required more electricity, so the movement combines the oscillator with power-saving measures and precision component design. The company’s technical pages explain the role of light and component precision in the movement.
Running time and movement thickness
Citizen’s 2018 specification gave the movement a thickness of 2.92 mm and a running time of six months on a full charge, even without further light. These are figures from the concept’s announcement. Current wristwatch pages describe six months of running time, with some specifying up to eight months when power-save is enabled; those descriptions apply to the listed wristwatch models, not necessarily to the pocket-watch concept.
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- 【Hand-Wind Mechanical Movement】 Enjoy traditional mechanical timekeeping without batteries. Simply wind the pocket watch manually before use to power the movement, bringing the classic experience of a traditional wind-up watch to everyday carry or display.
- 【Visible Mechanical Movement】 The transparent front dial and rear viewing window allow you to clearly see the gears and mechanical movement working from both sides. The moving components add visual interest and make the watch especially appealing for display and collecting.
- 【Vintage Bronze-Tone Design】 Finished in an antique bronze tone with decorative engraved patterns and classic Roman numeral hour markers, this mechanical pocket watch delivers an old-world look that pairs naturally with suits, waistcoats, vintage outfits and steampunk-inspired styling.
- 【45 mm Pocket Watch with Chain】 The watch measures approximately 45 mm in diameter and includes a 25 cm chain for attaching to a vest, suit or pocket. Its traditional round profile combines decorative styling with convenient everyday carrying.
- 【Gift-Ready Presentation】 Presented in an elegant gift box with the pocket watch, chain and instruction manual inside. Its visible mechanical movement and vintage appearance make it a distinctive gift for fathers, husbands, boyfriends, sons and collectors for birthdays, Father’s Day, Christmas, anniversaries and other special occasions.
Can you buy the pocket watch?
No. Citizen explicitly identified the 2018 pocket watch as a concept model “Not for sale.” Caliber 0100 is available as a wristwatch collection, but those watches are not the anniversary pocket watch. Check Citizen’s product page for current models and availability in your region.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What makes the concept notable?
The pocket watch brought together two ideas: a modern, light-powered quartz movement and a format that recalled Citizen’s early history. Its significance is the technology Citizen chose to demonstrate—an oscillator operating at a much higher frequency than conventional quartz, paired with energy-saving engineering—not a claim that the concept was independently proven to outperform every other watch. The ±1-second-per-year figure should be read as Citizen’s specification, since the available sources do not establish an independent comparative test.
Quick Recap
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- SEE TIME COME TO LIFE Enjoy watching time move, not just pass. Skeleton dial and exhibition case-back reveal the inner mechanism, making it a standout piece for collectors and anyone who appreciates mechanical design.
- TRACK TIME ACROSS LOCATIONS Stay aware of time beyond your current location. Dual time GMT subdial helps track a second time zone, while the sun and moon display shows day and night at a glance.
- NO BATTERY, JUST WIND AND GO Use it without worrying about charging or batteries. Mechanical movement powered by hand-winding keeps it running smoothly with a simple daily routine.
- BUILT FOR STYLE AND GIFTING Make a lasting impression for special occasions. The Modena 991 has an Engraved, see-through skeletonized dial and exhibition case-back with vintage styling making it a strong choice for gifts, collections, or formal wear.
- MORE THAN A POCKET PIECE Display it when you're not wearing it. Integrated hinge allows it to stand upright, turning it into a functional desk clock for your workspace or home.
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- Pocket watch dial: The white dial with black Roman scale and pointer is easy to read time. It is a practical item and can be used as a clock for daily use.
- Opening method: quartz pocket watch is simple in design; You can press the crown on the top of the watch, and the front panel will open to set the time: pull the crown out of the watch base, and turn the crown clockwise until the exact time is reached.
- Wearing chain: With a detachable chain, it is easy to assemble and disassemble, making the pocket watch look more complete.
- Case Diameter:1.81 inches(46mm); Chain Length:14 inches(365mm).
- Quartz movement : Quartz movement is adopted, with accurate timing, light weight, convenient maintenance and use. Different from mechanical pocket watch, it does not need to be worn on the chain. (The package contains a quartz movement for your replacement).
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