A number, not a feeling
“It runs a little fast” is a hunch. After a day on your wrist, Réglage gives you the figure: +2.8 seconds a day, measured against atomic time.
For mechanical and automatic watches
Know your watch to the second.
Réglage sets your watch to atomic time, to the second, then tells you exactly how many seconds a day it gains or loses. A quiet instrument for people who still wear a machine on their wrist.
00:00:00 Local time
Why Réglage
A mechanical watch is a small machine that typically beats six or eight times a second, driven by a spring and nothing else. It will never be perfect. That is the charm of it, and the reason to know it well.
The chronometer standard
A COSC-certified chronometer’s movement must average between −4 and +6 seconds a day. Réglage shows you, plainly, whether your watch stays within the same range on your wrist.
See the drift before it matters
Every session stays in its history. A watch that runs a little further off each time is quietly asking for a service, and after one, you’ll know within a day whether the watchmaker’s regulation holds.
How it works
Three steps. One number.
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01
Set
The dial runs on atomic time and counts down to every fifth second; turn on the tones and a soft buzz if you like. Pull the crown (on most watches the seconds hand stops), set the time and push it home on the mark.
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02
Wear
Live your day. Wind it, wear it, leave it on the nightstand. The longer you wait, the sharper the answer; a full day gives a reliable one.
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03
Measure
Choose a moment just ahead of your watch and tap Now as its seconds hand arrives. Réglage works out the rate, in seconds per day, and keeps it.
The result
Your watch, in one figure.
The rate, whether it keeps to chronometer tolerance, a chart of the session as it settles and the history of every session before it. Not a timegrapher’s five-minute snapshot, but how your watch actually runs on your wrist, day after day.
Field watch
Session 3 · 4 d
+2.8s/d
Within COSC chronometer tolerance (−4 to +6 s/d)
- Session 2 · 6 d+3.4 s/d
- Session 1 · 3 d+4.1 s/d
The finer points
Small things, done carefully.
Atomic time
The dial is synchronized to atomic time over the internet, accurate to a fraction of a second.
Heard and felt
Turn on the tones and rising pitches lead you to every fifth second, with a gentle buzz on each one in between. Eyes stay on your watch.
Your whole collection
Every watch keeps its own sessions, its own chart and its own history.
On every device
Sign in with a code sent to your email, no password. Your watches follow you.
Works offline
No signal? Your watches and measurements stay on your phone and sync when you’re back online.
Yours to keep
Export all your data whenever you like. Delete your account and it all goes with it.
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Questions
Questions, answered to the second.
How do I set my watch to the exact second?
Open Réglage and let the dial count down: it runs on atomic time and marks every fifth second, with rising tones and a soft buzz if you like. Pull the crown, set the hands, and push the crown home exactly on the mark. Your watch then starts within a fraction of a second of atomic time.
What are hacking seconds?
A watch with hacking seconds stops its seconds hand when you pull the crown out, so you can hold it at the top of the dial and restart it on the exact second. Most modern mechanical watches have it; many older and some affordable ones don’t.
How do I set a watch without hacking seconds?
You can’t stop its seconds hand, so set the minutes as closely as you can and let Réglage do the rest. Measure once to start a session: Réglage records how far off the watch is as its starting point, and works out the rate from how that changes. The watch doesn’t have to start on the exact second.
How accurate should an automatic watch be?
It depends on the movement. A COSC-certified chronometer averages −4 to +6 seconds a day; a Rolex Superlative Chronometer −2 to +2 after casing; most Omega Master Chronometers 0 to +5; a Grand Seiko mechanical −3 to +5; and an everyday Seiko 4R36 movement is specified at −35 to +45. A steady rate within your movement’s specification is a healthy watch.
What does COSC chronometer certified mean?
COSC, the Swiss Official Chronometer Testing Institute, tests a movement for 15 days in five positions and at three temperatures, following ISO 3159. To be certified, it must average between −4 and +6 seconds a day. Since 2026, COSC also certifies complete watches as Excellence Chronometers, at −2 to +4 seconds a day.
How long should I measure?
At least 12 hours, and better a full day or more. Each measurement can be a few tenths of a second off, depending on how exactly you tap, and that error is spread over the time in between: over a day it hardly counts, over an hour it would be twenty-four times larger. That’s why Réglage asks you to wait 12 hours before measuring again.
Why is my watch running fast?
Often magnetism: a phone, laptop or bag clasp can magnetize the hairspring and make a watch gain seconds or even minutes a day. The position it rests in overnight, a low power reserve, a knock, or a movement that’s due for a service play a part too. If the rate jumps from one session to the next, suspect magnetism; if it drifts further off session after session, a service is due.
Does Réglage replace a timegrapher?
It answers a different question. A timegrapher listens to the movement for a few minutes on a desk and shows rate, beat error and amplitude, which a watchmaker needs. Réglage measures what you live with: how your watch keeps time on your wrist, over a day or more. For an owner, that is usually the number that matters.
réglage /ʁe.ɡlaʒ/
noun, French
The watchmaker’s art of adjusting a movement until it keeps time. The last and finest step in making a watch, and now one you can check yourself.
Your watch has kept time for you. Return the favor.
Réglage is made for iPhone and Android.