Eco-Drive with
Annual Accuracy of ±5 Seconds

More More

年差±5秒、あくなき高精度の追求。

Features 01

Annual accuracy of ±5 seconds:
The unrelenting pursuit of precision

The basic mission of a watch is straightforward: to tell the accurate time. Since the birth of the brand, The CITIZEN has been wholehearted in pursuing the essence of the watch. Even if you use this watch for all 365 days of the year, timekeeping deviation will never exceed 5 seconds. The ultraprecise movement we developed uses only the most rigorously selected crystal oscillators and is assembled from individual components of extraordinary precision. More unusually, we achieved this extreme level of accuracy using CITIZEN’s proprietary Eco-Drive technology. We created a watch that tells the accurate time and keeps on running powered only by light, without the need for regular battery replacement.

Accuracy

The crystal oscillators are
set aside for 6 months

For quartz watches, the quality of the crystal oscillator inside the movement is crucial for accurate timekeeping. The CITIZEN is not prepared to use even the highly accurate crystal oscillators used in most quartz watches without first subjecting them to rigorous testing. For our models with annual accuracy of ±5 seconds, we set aside freshly manufactured crystal oscillators for a six-month observation period, before selecting only those that meet our demanding standards of accuracy. The crystal oscillators are again tested repeatedly after being built into the movement.

Accuracy

Taking its own temperature
1,440 times in a day

The variable with the greatest impact on the crystal oscillators’ accuracy is temperature. A quartz watch which tells the correct time at 25 degrees Celsius slows down by 0.1 seconds per day for every 5-degree-Celsius temperature change. That may not be a serious issue for your run-of-the-mill quartz watch, but for a watch that measures its accuracy on a yearly basis like The CITIZEN, 0.1 seconds per day constitutes a major deviation in annual terms. That explains why we equipped The CITIZEN with a temperature correction function that automatically monitors the watch’s internal temperature in 0.1-degree increments 1,440 times per day, making any necessary adjustments. Constantly compensating for frequency changes resulting from temperature change maintains strict accuracy.

Assembly

The master artisans who
breathe life into our watches

The CITIZEN watches are made at CITIZEN's special watch workshop nestled deep in the Nagano countryside. With their specially designed and highly advanced movements, the work requires extraordinary skill. That is why the task is entrusted to our watchmaking Meisters, our most experienced and technically proficient artisans. With their acutely sensitive fingers and cultivated instincts, they breathe life into the individual The CITIZEN products. Each watch is a microcosm of CITIZEN craftsmanship.

The master artisans who breathe life into our watches