Crystallised Essence of Time : Caliber 0100

Crystallised Essence of Time

The most precise light-powered watch in the world*
with annual accuracy of ±1 second.
The crystallisation of CITIZEN’s technology,
craftsmanship and philosophy of watchmaking,
all refined into the Caliber 0100.
Let's talk about the technology behind this precise accuracy. 

01) A quest for the perfectly
pure second

A light-powered watch that tells the world’s most precise time with accuracy of ±1 second per year.
Where does this level of precision come from?

The second hand of a watch counts out 31,536,000 seconds every year.
A watch with accuracy of ±1 second per year must mark those millions of seconds with annual deviation within just one second.
To mark the seconds with such perfect purity,
all the watch’s individual components need to be made with greater precision.

That is the challenge for near zero deviation.
We elected to use an AT cut crystal oscillator in place of the tuning fork-shaped one used in most quartz watches.
We then focused on making the individual components—the hands, gears, motor, circuit, and so on—more precise.
Finally, by bringing in Eco-Drive light-powered technology, we created a watch that needs only light to keep telling the time with accuracy of ±1 second per year.

Created by CITIZEN’s advanced technologies,
the perfectly pure individual second takes shape,
resulting in perfect purity and precision.

02) Technology to keep
marking the individual
seconds precisely

Ever since CITIZEN began making watches, the challenge of achieving greater precision has been a key mission.
After creating a purer, more refined individual second by rethinking the crystal oscillator, the next challenge we faced was how to keep marking those seconds precisely, reliably and beautifully with light as the sole power source.

You cannot make a watch accurate to ±1 second per year without insisting on precision in every element that goes into it.
We succeeded in making this watch because we are a manufacture d’horlogerie and developed all the components from scratch.

A second hand that moves with force and beauty

03) Expressing the beauty
of each individual second

Every second marked by this watch is like a single line of poetry.
There you can discover time in all its profundity: the moment and the eternal; the rigour that forbids even a second’s deviation; a clear borderline between past, present and future; and quality like a finely polished crystal.

The expression of this watch is one of extreme simplicity: Simplicity that reflects the mechanism’s intention to mark the individual seconds in all their perfect purity.

A beautifully curved second hand


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*As of February 2019, for an autonomous analogue quartz watch, according to research by Citizen Watch Co., Ltd.