Mechanical watches are wonderfully simple to live with once you know a few basics. But if you are wearing an automatic watch for the first time — or have just finished building your own — setting the time and date can be surprisingly confusing.
Which crown position sets the date? How do you know whether the watch is showing AM or PM? Should you wind it first? And why do people warn you not to change the date around midnight?
In this guide, we'll show you how to set an automatic watch correctly, using the Seiko Instruments NH35 automatic movement found in Horologic watchmaking sets as our example.
Before you start: understanding the crown positions
The NH35 has three crown positions:
Position 0 – Crown pushed in
This is the normal position while wearing the watch. Turning the crown in this position manually winds the movement.
Position 1 – Crown pulled out one click
This position allows you to quick-set the date.
Position 2 – Crown pulled out two clicks
This position sets the time. Pulling the crown to this position also stops the seconds hand, a feature known as hacking seconds.
Now let's set the watch.
How to set an automatic watch correctly
There are several ways to set a mechanical watch, but the following method is particularly useful because it helps avoid accidentally changing the date while the date mechanism is engaged.
1. Give the watch some power
If the watch has stopped, start by winding it manually.
With the crown fully pushed in, turn it clockwise approximately 20–30 times. You should feel only light resistance.
This gives the movement enough energy to run reliably while you set it.
The NH35 is an automatic movement, so once you begin wearing the watch, the movement of your wrist will continue winding it.
2. Find midnight
Pull the crown all the way out to Position 2 and slowly move the hands forward.
Continue until the date changes.
The point at which the date changes tells you that the watch has just passed midnight.
This is important because a mechanical watch does not otherwise know the difference between, for example, 8:00 in the morning and 8:00 in the evening.
3. Move the hands away from midnight
Continue moving the hands forward until they show approximately 6:00.
You are now safely away from the period during which the date-change mechanism normally operates.
This is a good habit whenever you need to adjust the date on a mechanical watch.
4. Set the date to yesterday
Push the crown in one click to Position 1.
Use the quick-set function to change the date until the watch displays yesterday's date.
Why yesterday?
Because we're going to advance the hands through midnight one more time. When the date changes, you'll know with certainty that you've entered the current day.
5. Set the correct time
Pull the crown back out to Position 2.
Move the hands forward.
When they pass midnight, the date will change from yesterday to today.
Now continue moving the hands forward until you reach the current time.
If it is currently in the afternoon or evening, make sure you pass 12:00 noon before reaching the correct time.
For example, if it is 4:30 PM, advance the hands through midnight, past 12:00 noon, and then to 4:30.
This ensures the watch will change date at midnight rather than at noon.
6. Push the crown back in
Once the time is correct, push the crown fully back into Position 0.
The seconds hand will begin moving again, and your watch is ready to wear.
The important rule: don't quick-set the date around midnight
If you remember only one thing from this guide, make it this:
Avoid using the quick-set date function when the watch is close to midnight.
Mechanical date movements don't change the date instantaneously. Internally, gears begin engaging before the visible date actually changes.
If you use the crown's quick-set date function while those components are already engaged, you can put unnecessary stress on the date mechanism.
The exact engagement period varies between movements, so rather than trying to remember a precise number of hours, we recommend a simple rule:
Move the hands to around 6:00 before using the quick-set date function.
That way, you don't need to guess whether the watch is showing 11 PM or 11 AM.
Why does my automatic watch change date at noon?
This is one of the most common mistakes when setting a mechanical watch.
If your date changes around lunchtime instead of midnight, nothing is necessarily wrong with the movement.
The watch has simply been set 12 hours out of phase.
To correct it, pull the crown out to the time-setting position and move the hands forward by 12 hours.
The date should then change around midnight as intended.
How do you wind an automatic watch?
An automatic movement is wound primarily by movement.
Inside the watch is a weighted rotor that rotates as you move your wrist. That movement winds the mainspring and stores energy.
But most modern automatic movements, including the NH35, can also be wound manually.
With the crown pushed in, turn it clockwise. If the watch has completely stopped, around 20–30 turns is a useful starting point before putting it on.
After that, normal daily wear will usually keep the watch running.
Can you overwind an NH35?
Under normal use, you don't need to worry about overwinding an NH35.
Unlike a traditional hand-wound movement, an automatic movement uses a mechanism that allows the mainspring to slip once it reaches its intended level of tension.
That means continued movement of the rotor doesn't keep tightening the mainspring indefinitely.
There is therefore no need to count crown turns precisely. The initial 20–30 turns are simply an easy way to give a stopped watch enough power to get going.
How long will an NH35 run without being worn?
The NH35 has a power reserve of approximately 41 hours when sufficiently wound.
That means if you take your watch off on Friday evening and don't wear it again until Monday morning, it may have stopped.
This is completely normal.
Simply wind it, set the time and date again, and you're ready to go.
One of the charms of a mechanical watch is that it isn't permanently powered by a battery. It stores mechanical energy while you wear it and gradually releases that energy to keep time.
Do I need a watch winder?
For a simple automatic watch such as an NH35-powered watch, generally no.
If the watch stops because you haven't worn it for a few days, there is nothing wrong with leaving it stopped.
When you want to wear it again, simply wind and set it.
Watch winders can be convenient for watches with complicated calendars that are tedious to reset, but for a straightforward time-and-date automatic watch, resetting it takes less than a minute.
How accurate is an NH35 automatic movement?
A mechanical watch should not be expected to behave like a quartz watch or a smartphone clock.
The NH35's manufacturer specification allows for a daily rate of approximately -20 to +40 seconds per day, although individual movements can perform better than this in normal use.
Mechanical accuracy can also vary depending on temperature, how fully wound the watch is, how active you are, and the position in which the watch rests overnight.
A small amount of daily variation is therefore part of owning a mechanical watch rather than necessarily a sign that something is wrong.
Which direction should you turn the crown?
On an NH35:
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With the crown pushed in, turning it clockwise manually winds the movement.
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With the crown pulled out one click, the crown operates the quick-set date.
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With the crown pulled out fully, turning the crown moves the hands to set the time.
Don't force the crown if something feels unusually resistant.
Mechanical movements contain very small components. Setting a watch should require controlled, gentle movements rather than force.
What if your automatic watch has stopped?
Usually, there is nothing to worry about.
If an automatic watch hasn't been worn long enough to keep the mainspring charged, it will eventually use its remaining power reserve and stop.
To restart it:
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Wind the watch approximately 20–30 turns.
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Pull the crown fully out.
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Advance the hands until you identify midnight.
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Move the hands to around 6:00.
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Set the date to yesterday.
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Advance through midnight and set today's correct time.
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Push the crown back in and wear the watch.
Once you've done it a couple of times, the entire process becomes second nature.
A mechanical watch is meant to be interacted with
Setting and winding a mechanical watch is part of what makes owning one different from checking the time on a phone or wearing a battery-powered watch.
There is a physical connection between what happens inside the movement and what you do with the crown.
And if you have built the watch yourself, that connection becomes even more tangible.
You aren't simply setting a watch. You're operating the same movement whose dial you fitted, hands you installed and case you assembled.
That's what makes mechanical watchmaking so fascinating.
Want to experience the process yourself?
Discover the Horologic Watchmaking Sets and build your own automatic watch — from fitting the dial and hands to casing the movement and wearing the finished watch on your wrist.