Adjusting a mechanical watch's running rate to reduce how much time it gains or loses.
The daily rate is how much a watch gains or loses over 24 hours against a reference time. A watch runs fast when its balance and balance spring oscillate at too high a frequency, and slow when the frequency is too low. Once the movement is assembled, a watchmaker checks the rate with a timing machine and makes fine adjustments to the balance and spring system.
On movements with a regulator, moving its pins changes the active length of the spring: moved away from the stud, the pins shorten the spring and the watch gains; moved toward it, the watch loses. A variable-inertia balance needs no regulator: screws or weights on its rim are moved inward to make the watch run faster, outward to slow it. The corrections are small: by Horopedia’s calculation, a medium wristwatch losing 10 seconds a day needs its spring shortened by about 0.02 mm.
In job listings
Regulation appears in production watchmaker roles and apprenticeships, in specialist regulator roles, and in after-sales service and restoration roles, where restoring a watch includes regulating it. It signals work at the bench with a timing machine, sometimes on vintage and complicated watches. See current regulation roles.
