An automatic watch loses or gains a few to a dozen seconds per day, and that's normal. Here's the specifics: what's a normal deviation, how to measure it at home, and when you really need to take it to a watchmaker.
How much can an automatic watch deviate?
A mechanical movement isn't, and won't be, as accurate as a quartz one. This isn't a flaw, but a consequence of the design—the rhythm is determined by the spring and balance, and is influenced by temperature, position, and winding. All models in the collections Horizon, Astra i Nebula they have an automatic mechanism, so exactly the same principle applies to them.
- −10 to +20 seconds per day — typical range for popular Japanese calibers in this price range.
- ±5 seconds — very good result, found after additional adjustment.
- over 40 seconds — this is already a signal that something needs to be checked.
For comparison: a quartz watch is usually off by a dozen or so seconds per month. If accuracy is all you care about, an automatic will never be the right choice—you buy it for the mechanics, not the precision.
How to measure deviation at home
You don't need any equipment. Just a phone with the exact time.
- Set your watch to the exact second using the atomic clock on your phone and write down the time.
- Wear it normally for 3–5 days as you normally would.
- Compare again and divide the difference by the number of days.
A single day of measurement means nothing—the deviation varies depending on whether the watch was placed face up or on the wrist. Only an average over several days is reliable.
What affects accuracy
- Sleeping position. A watch that sits crown-up runs differently than a watch that sits face-down. If it's too fast, try placing it in a different position—this is the easiest way to adjust the time without opening the case.
- Tension level. When the power reserve is depleted, the watch runs less smoothly. With a 48-hour power reserve, the last few hours tend to be the least stable.
- Magnetic field. Speakers, bags with magnetic closures, phone cases. A magnetized watch can start to lose several minutes a day—this is the most common cause of a sudden change.
- Temperature. Large differences affect the elasticity of the hair balance.
When to go to a watchmaker
Four situations where it is worth it:
- The deviation exceeds 40 seconds per day and persists despite changes in position.
- The watch suddenly started to lose minutes - most likely magnetization or demagnetization is a matter of minutes and a small cost.
- The power reserve has noticeably shortened.
- It's been several years since the last inspection.
Japanese automatic movements are serviced by most watchmakers in Poland, so it is neither expensive nor troublesome.
Frequently asked questions
Does a more expensive watch keep more accurately?
Not always. It's the caliber and whether someone adjusted it that matters, not the final price. More on that in the text. how much does a good automatic watch cost.
Can I adjust the watch myself?
Adjusting the watch requires opening the case and tools—a task for a watchmaker. If you're not comfortable with the positioning, you can experiment with the nighttime setting.
How long does the power reserve last in your watches?
Approximately 48 hours. You can check this in the specifications of each model in the collections. Zenith, Horizon i Skeleton.
