Hacking seconds, also called stop-seconds, lets you stop the seconds hand while setting a watch. This makes it easier to align the display with a reference time. It does not adjust the movement’s running rate: a watch set precisely this morning can still gain or lose time during the day.
Identify the time-setting position
Read the instructions for the actual calibre before pulling the crown. Winding, calendar correction and time setting may occupy different positions. Do not assume that the first click sets the time, or that crown-position numbers mean the same thing across manufacturers.
For example, NOMOS’s setting guidance distinguishes the DUW 6101’s outermost, third crown position from the second position used for time setting on its other automatic calibres. The important information is the function of each position on your watch. For a locking crown, our screw-down crown guide covers the separate unlocking and closing steps.
Prepare the watch and reference first
Start with a watch that has sufficient power, following its winding instructions. Complete any necessary calendar setup using its specified sequence and permitted adjustment times. Confirm morning or afternoon where that matters to the calendar. Stop-seconds does not make calendar correction safe at every hour.
Choose a clear reference that displays seconds, such as a correctly synchronised radio-controlled clock. Check its time zone and date before you begin. Put both displays where you can read them without repeatedly moving the watch or changing your grip.
Stop, align and restart
The Seiko 4R35/4R37 instructions describe pulling the crown to the time-setting position when the seconds hand reaches twelve, then returning it in accordance with a time signal. Follow your own model’s directions for moving the hands and taking up any setting play.
With the seconds hand stopped at zero, align the hour and minute hands for an upcoming full minute. When the reference reaches that minute, return the crown as instructed. For example, a watch prepared for 9:15 should restart at 9:15:00 on the reference. This is an illustrative sequence, not a measured accuracy result.
Check the result without forcing it
Confirm that the seconds hand has restarted and the crown is properly closed. If the hand does not stop as expected, check the movement’s instructions before trying again; do not improvise by applying reverse pressure to the crown.
A small initial offset can simply be recorded. Our daily timing log separates that starting difference from subsequent gain or loss. Explore more practical guidance in Watches & Wear.