Citizen 0910 Manual page 26

The accuracy of mechanical watch changes with the following conditions:
(1) Spring winding
(2) Posture
(3) Use environment (temperature/magnetic fields/shock etc)
(1) Spring winding
Full winding of the spring provides the most stable energy for mechanical watches, and
ensures continued stable use.
(2) Posture
Mechanical watches are affected by gravity. When worn on the wrist, the watch will go
through various postures (orientations), and be subjected to changes in the direction of
gravity, which may affect its accuracy.
Mechanical Watches
25