As a matter of principle, keep your watch as far away from magnetic fields as possible. Mechanical watch movements all contain parts that can be magnetized, depending on the strength of the magnetic field.

Defying the laws of physics: certain watch models, feature an inner case made of soft iron as additional protection against magnetism.

According to the DIN 8309 standard, a watch is classified as anti-magnetic if it continues to function satisfactorily when exposed to a homogeneous magnetic field with a strength of 4800 A/m, or approximately 60.3 oersted. In today's world we are continuously exposed to electromagnetic fields of differing strengths. The strongest fields we encounter in the course of our everyday lives are those generated by televisions, computer screens, power lines and radio masts.

The metal case of a wristwatch functions rather like a Faraday cage and protects the movement against most magnetic fields. Nevertheless, a watch movement can be magnetized unintentionally. If this happens, it will inevitably be less accurate and the rate will be irregular. If this does happen, your watchmaker has special equipment that will demagnetize a mechanical watch quickly and simply.

In the case of a quartz watch, the entire procedure is all a little more difficult. Quartz watches have a stepping motor that contains a rotor with a permanent magnet, whose strength is affected by external magnetic fields and, in a worst case scenario, can even be destroyed. In short, avoid exposing your wristwatch to strong magnetic fields over extended periods of time.