See the real difference between a hacking movement (seconds hand stops) and a non-hacking movement (seconds hand keeps running). Interactive demo + clear guidance on when it matters.
Watch the seconds hand, then pull the crown
Hacking seconds means the balance wheel (and therefore the seconds hand) stops when you pull the crown to the time-setting position. This lets you set the watch to the exact second.
Non-hacking movements keep running when the crown is pulled. You have to synchronise the time while the seconds hand is still moving.
• You want to set the watch precisely to a reference time signal
• You care about synchronising multiple watches to the same second
• You frequently reset the time (travel, schedule changes)
For normal daily wear, many people never notice the difference. Non-hacking watches are still perfectly usable — you just synchronise on the fly.
| Movement | Hacking | Notes |
|---|---|---|
| Seiko NH35 / NH36 / 4R | Yes | Very common, reliable |
| Seiko 7S26 / 7S36 | No | No hand-wind either |
| Miyota 8215 | No | Affordable workhorse |
| Miyota 9015 | Yes | Higher grade |
| ETA 2824 / Sellita SW200 | Yes | Industry standard |
| ETA 2892 / SW300 | Yes | Thinner, high quality |
| Most modern Rolex / Omega | Yes | Standard on current models |
1. Pull the crown to the time-setting position.
2. Move the hands to about 15–30 seconds ahead of the reference time.
3. Hold the crown ready to push in.
4. Push the crown in exactly when the reference time reaches your set time.
With practice this becomes quick and accurate enough for everyday use.
Does hacking improve accuracy? No. Hacking only makes precise time-setting easier. The daily rate of the movement is separate.
Why do some cheaper movements omit hacking? It simplifies the movement and reduces cost. Many excellent older and budget movements were built without it.
Can a non-hacking watch be modified to hack? Usually not practical. It requires a different keyless works design. Better to choose a movement that already hacks if you need the feature.
Is the Seiko 7S26 bad because it doesn’t hack? No. It is a robust and proven movement. The lack of hacking and hand-winding are design choices, not defects.
Do quartz watches hack? Most quartz watches stop the seconds hand when the crown is pulled, so they behave like hacking movements for time setting.