The best of watchmaking at Watches & Wonders from April 1 to 7
The world's largest annual watchmaking trade show opens its doors again from April 1 to 7, 2025.
The COSC
The measurement of time
The COSC is the universally recognized and independent label awarding the official title of chronometer to Swiss movements and watches.
In measuring, testing, and certifying precision, we work relentlessly to validate the excellence of the most presitigious watch brands.
Founded in 1973, the COSC was created from the shared vision of Swiss Made brands and public authorities to standardize precision measurement, ensuring the protection and continuity of Swiss watchmaking worldwide.
The origins of the COSC
- 164
- 65
- 7
- 350
A non-profit public interest association, the COSC embodies a collective ambition dedicated to Swiss watchmaking excellence.
At the heart of our organization
Precision Laboratories
State-of-the-art laboratories, custom-designed equipment, cutting-edge technologies... Measuring time is a continuous commitment
