Watches

Why Is My Automatic Watch Losing or Gaining Time?

MelexWorld Editorial June 26, 2026 11 min read

You strapped on a beautiful new automatic watch, set it to the second against your phone, and admired how it kept perfect pace. Three days later you glance down and it is running two minutes behind. Your stomach drops. Did you buy a lemon? Almost certainly not. What feels like a defect is usually your watch behaving exactly as a tiny mechanical engine should. Understanding the difference between "wrong" and "normal" is the first step to loving a mechanical timepiece rather than fretting over it.

An automatic watch is not a quartz watch, and it was never meant to be. Inside the case, a coiled mainspring, a swinging weight, and a balance wheel oscillating several times per second do the work that a battery-powered crystal handles effortlessly. That mechanical heart is what makes these watches so desirable, and it is also why a little drift is part of the deal. Let's separate the harmless from the fixable so you know exactly when to shrug and when to act.

Is My Automatic Watch Losing Time Normal or Broken?

Some daily drift is completely normal for an automatic watch, and most healthy movements run anywhere from about -20 to +40 seconds per day depending on quality. Losing or gaining a handful of seconds is not a fault. It becomes a real problem only when the deviation is large, sudden, or keeps getting worse over time.

Here is the honest benchmark most owners never hear at the point of sale. A standard, non-certified automatic movement typically keeps time within roughly -10 to +15 seconds per day when it is healthy and well wound, though entry-level movements can sit closer to 20 or 30 seconds per day and still be perfectly within spec. A watch carrying COSC chronometer certification is held to a far tighter standard of -4 to +6 seconds per day, tested over 15 days across five positions and three temperatures. The finest in-house movements can reach +/-2 to +/-4 seconds per day. So before you panic, ask the real question: how many seconds per day is it actually drifting, and is that number stable?

How to Measure Watch Accuracy in Seconds Per Day

To measure watch accuracy properly, set your watch precisely to a reliable reference, then compare it against that same reference after several days without touching the crown. Divide the total gain or loss by the number of days, and you have your true rate in seconds per day.

One glance at a clock is not data. Do this instead:

Set the watch to the second against an atomic or phone clock and note the exact date and time.
Wear it normally, or rest it in one consistent position if you want a clean reading.
After three to seven days, check the deviation against the same reference.
Subtract, then divide by the number of days.

A longer observation window gives a far more reliable average, because a single day can be skewed by how active you were or how the watch rested overnight. Track it across a week and the honest picture appears. If your watch is losing four seconds a day, that is around 28 seconds over a week, and that is a genuinely well-behaved automatic, not a broken one.

Why Is My Automatic Watch Losing Time? The Real Causes

Most automatic watches lose time for one of a few practical reasons: a low power reserve, an inconsistent wearing routine, magnetism, the position the watch rests in, a hard knock, or a movement simply due for service. The good news is that several of these you can diagnose and fix yourself in minutes.

Low Power Reserve Is the Most Common Culprit

A watch running low on power is the single most frequent reason an automatic starts losing time. As the mainspring unwinds toward empty, it can no longer deliver energy at a steady rate, and the balance wheel loses amplitude, causing the watch to run slow or eventually stop.

Automatic watches are usually regulated to perform their best while fully wound. When the power reserve drops below roughly 10 percent, timekeeping can fall off noticeably. If you wear your watch only a few hours a day, or you rotate between several watches, the movement may never reach a full wind from wrist motion alone. This is the classic trap for people who own more than one watch and cannot understand why each one seems to lag.

The fix is simple. When you put the watch on, hand-wind the crown roughly 20 to 30 turns to top up the mainspring rather than relying on your daily movement to do all the work. A well-fed automatic is an accurate automatic.

Magnetism Usually Makes a Watch Gain, Not Lose

Magnetism is the usual suspect behind an automatic watch gaining time, sometimes dramatically. When the hairspring becomes magnetized, its coils cling together, the balance effectively shortens its swing, and the watch can suddenly gain 30 seconds, a full minute, or even several minutes per day.

Modern life is full of magnets. Laptop lids, tablet covers, phone cases, speaker grilles, magnetic handbag clasps, and refrigerator doors can all magnetize a movement without you noticing. If your watch went from reliable to wildly fast overnight, magnetism is the first thing to rule out. A quick home test: lay a simple analog compass flat, bring the watch slowly toward it, and watch whether the needle deflects. If it swings, your watch is magnetized.

Position, Shocks, and a Movement Due for Service

Where a watch rests and how it gets treated both shape its rate. Gravity pulls unevenly on the balance wheel depending on whether the watch lies dial up, dial down, crown up, or on its side, so a watch can gain a few seconds in one position and lose a few in another. A single hard knock can also disturb the hairspring, and a movement that has gone years without service will drift as its lubricants dry out and friction builds.

Shocks matter more than people expect. A forceful impact can jostle or tangle the hairspring coils, producing a real and lasting change in rate. And every mechanical watch has a service interval, typically around every five years, after which old oils thicken and the movement simply cannot hold its numbers. If your watch has quietly drifted worse and worse over a long stretch with no other explanation, age is likely the answer.

Automatic Watch Timekeeping: Causes and Fixes at a Glance

Before we get to the hands-on fixes, here is a quick reference that maps each common symptom to its likely cause and the practical solution. Use it to diagnose your own watch in under a minute.

Symptom	Likely Cause	What To Do
Loses a few seconds per day, steady	Normal movement tolerance	Nothing; this is healthy
Runs slow, especially in the morning	Low power reserve	Hand-wind 20-30 turns when you put it on
Suddenly gains minutes per day	Magnetized hairspring	Test with a compass, then demagnetize
Rate changes with how you set it down	Positional variation	Rest it in a favorable position overnight
Slow or erratic after a hard knock	Shock to the hairspring	Have a watchmaker inspect and regulate
Gradually worse over years	Old lubricants, due for service	Book a full professional service
Consistently fast or slow every day	Needs regulation	Watchmaker adjusts the rate on a timing machine

How to Fix an Automatic Watch That Is Losing or Gaining Time

Many timekeeping problems can be solved at home with a few simple habits, while others call for a watchmaker's timing machine. Start with the free fixes: wind it fully, wear it consistently, check for magnetism, and experiment with resting position. If the drift survives all of that, professional regulation or service is the answer.

Wear It More and Keep It Wound

Consistency is quietly the most effective fix of all. An automatic that lives on your wrist all day, or gets a proper hand-wind each morning, holds a full mainspring and therefore a steadier rate. If you own several watches, consider a watch winder or simply hand-wind whichever one you are putting on. Do not lean on wrist motion alone to revive a fully unwound watch, because it can take a long time and still leave the reserve low.

Demagnetize a Magnetized Watch

If the compass test flagged magnetism, the cure is fast and often dramatic. A watch demagnetizer is an inexpensive tool that emits an alternating magnetic field to neutralize the charge. Rest the watch on or just above the pad, hold the button, then slowly lift the watch away over about a foot before releasing. Heavily magnetized watches may need two or three passes, particularly after exposure to something strong. Any watch shop can also do this for you in seconds, usually for little or nothing.

Use Resting Position to Nudge the Rate

Here is a trick most owners never learn. Because gravity affects the balance differently in each orientation, you can partly compensate for a small drift by choosing where the watch sleeps. As a general tendency, resting a watch crown up nudges it slower and helps cancel out a gain, while lying it dial up tends to have the opposite effect. If your watch runs a touch fast, experiment with a crown-up resting position overnight and measure the difference over a few days. It will not fix a broken watch, but it can quietly tidy up a few seconds.

Regulate the Watch Professionally

When a watch is consistently fast or slow by more than about 20 seconds per day, or nothing at home moves the needle, it is time to regulate it. A watchmaker places the movement on a timing machine, fine-tunes the regulator, and can typically bring the rate to within a few seconds per day. Regulation is often a quick job costing somewhere in the region of $50 to $150, far less than owners fear. If the movement is also years overdue, a full service is the more complete fix.

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Frequently Asked Questions

Is it normal for an automatic watch to lose 10 seconds a day?

Yes, losing around 10 seconds a day is well within normal range for most automatic watches. Standard movements are generally considered healthy anywhere from roughly -10 to +15 seconds per day, and entry-level pieces a little wider than that. Only COSC-certified chronometers are held to the tighter -4 to +6 seconds per day standard, so 10 seconds is nothing to worry about.

Why does my automatic watch lose time overnight when I take it off?

Overnight losses usually come down to power reserve and resting position. Off the wrist, the watch no longer receives winding motion, so its mainspring slowly unwinds and the rate can dip, especially if the reserve was already low. The position it rests in also matters, since gravity affects the balance differently dial up versus crown up. Hand-winding before bed and choosing a consistent resting spot both help.

Can a magnet permanently damage my automatic watch?

In most cases, no. Everyday magnets typically magnetize the hairspring, which makes the watch run fast but does not cause permanent harm. Demagnetizing the watch restores normal timekeeping, and it can be repeated if needed. Only extreme exposure or a physical shock alongside it would risk lasting damage, and even then a watchmaker can usually correct the rate.

How often should an automatic watch be serviced to stay accurate?

Most automatic watches benefit from a full service roughly every five years, though the exact interval varies by movement and how hard the watch is worn. Over time, the lubricants inside dry out and friction increases, which slowly degrades accuracy no matter how carefully you treat the watch. If yours has drifted steadily worse over several years, a service is likely overdue.

An automatic watch that runs a few seconds off each day is not misbehaving. It is a small mechanical marvel doing precisely what it was built to do, and once you know how to read its rate, wind it properly, keep it away from magnets, and rest it thoughtfully, you gain something a quartz watch can never offer: a relationship with a living machine on your wrist. Measure it honestly, care for it simply, and reach for a watchmaker only when the numbers truly call for one.

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