Hacking Function
A watch function or complication known as Hacking Function, adding information or capability beyond basic time display.
Also known as: Hacking seconds, Stop seconds, Stop-seconds, Seconds stop
Definition
A hacking function stops the running seconds indication when the crown is pulled to the time-setting position, allowing the watch to be synchronised precisely to a reference time. In a mechanical movement, a small lever typically contacts or otherwise arrests the balance system when the setting mechanism is engaged. Pushing the crown back in releases the balance and the watch resumes running. It is also called stop-seconds or hacking seconds.
Why it matters
Hacking does not make a watch inherently more accurate, but it makes accurate setting much easier—particularly when synchronising several watches or setting against an official time signal.