The incredible precision of chronometer watches

Only three per cent of Swiss watches are certified chronometers, and for good reason.

August 28, 2016

Man’s ability to measure time accurately has taken quantum leaps since the time when the Quran was first written down.

Back then, I can imagine, the world was a different place. Telling time accurately was limited to devices like sun clocks, using poles or tall structures, or the sundial, and the water clock (also known as the clepsydra). I’m sure that such devices were quite marvelous at the time. With the perfection of glass blowing, the hourglass was added to the list.

Still, determining time accurately was mostly a hit and miss thing, and when clouds covered the sky, sunrise and sunset were a little more difficult to determine. Much later we invented mechanical clocks, and these too, I am happy to say, have come a long way since the first ‘beta’ version. 

chronometer watches breitling Navitimer AOPA.jpg Breitling is one of the world's only major watch brands to equip all its models with chronometer-certified movements.

Later still we were introduced to the chronograph. The first modern chronograph, a device of unparalleled accuracy, was invented by Louis Moinet in 1816, and it was used for astronomical calculations. 

What is a chronograph? Well, basically it is a watch that measures seconds, with either a stop-watch or bezel scale, and often has sub-dials showing minutes and hours. These became popular in a whole range of sporting events, where accurate timing was important. 

As the Swiss watchmaking industry developed and refined its technology, the pursuit of perfection in timekeeping was the goal. Then, in 1973 five watchmaking cantons came together to create an independent testing and certification body to certify the most accurate watches in the world – it was called the COSC. Now watches of unmatched accuracy could be tested and certified as chronometers.

“Chronometer” is a watch industry term for timing accuracy, and not all wristwatches are chronometers. To qualify, the mechanism must be rigorously tested over 15 days, under various conditions, and only once it has ticked all the boxes can it display the coveted “officially certified chronometer” badge.

Only around three per cent of Swiss watches earn this mark of distinction. The certification does not apply to digital, electronic watches.

These precision instruments became hugely popular with aviators, enabling them to perform quick and accurate distance and time calculations quite easily. Today, the “chronometer” label is a sign of excellence in watchmaking. 

Perhaps, being surrounded by so many watches every day, I am more sensitive to the subject than the average person. For me, though, there is a particular delight in knowing that a collection of mechanical moving parts can be designed to such a high level of precision.

Our world is changing, and the way we think of time is evolving too. There seems to be less time today, and ever more to do. So take a moment to consider that something we take for granted today – being able to tell the time with great accuracy – has not always been the case. 

Tariq Malik is owner of Momentum Dubai, the UAE's first and only vintage watch boutique. Visit