Impact
•Your watch is designed to withstand impact incurred during normal daily use and light activity such as playing catch, tennis, etc. Dropping the watch or otherwise subjecting it to strong impact, however, can lead to malfunction.
Note that watches with shock-resistant designs (G-SHOCK, Baby-G, G-ms) can be worn while operating a chain saw or engaging in other activities that generate strong vibration, or while engage in strenuous sports activities (motocross, etc.).
Magnetism
•The hands of analog and combination (analog-digital) watches are moved by a motor that uses magnetic force. When such a watch is close to a device (audio speakers, magnetic necklace, cell phone, etc.) that emits strong magnetism, the magnetism can cause timekeeping to slow down, speed up, or stop, resulting in the incorrect time being displayed.
Electrostatic Charge
•Exposure to very strong electrostatic charge can cause the watch to display the wrong time. Very strong electrostatic charge even can damage electronic components.