How to set a mechanical watch to the exact second
Stop the seconds hand, set the next minute, and push the crown in on the minute. Here is how to do it precisely, including on watches that do not hack.
What you need
An accurate reference clock and a watch with a hacking seconds hand, which stops when you pull the crown out. Most modern automatic and hand-wound watches hack. Your phone clock can be off by a second or more, so use a source that corrects for that.
Steps
- Wait until the seconds hand reaches 12, then pull the crown out to the time-setting position. The seconds hand stops.
- Turn the minute hand to one minute ahead of the current time. Go a little past the marker and come back onto it, so the gears take up their slack.
- Watch the reference countdown. When it reaches zero, push the crown in. The watch starts on the exact second.
If your watch does not hack
Set the minute hand to the coming minute while the watch runs. Then push the crown in so the watch keeps running, and nudge the minute hand only when the seconds hand is near 12. You will usually land within a second or two.