One possible reason for this is that your watch has been affected by magnetism. Magnetic fields are all around us in everyday objects including computers, televisions, fridges, magnetic fasteners on handbags, jewellery to name only a few. When a quartz watch comes in contact with a magnetic field, it stops. As soon as the magnetic source is removed, the watch starts running again. This may be perceived later as the watch running slow. In this case one need only reset the time. With a mechanical watch the steel components in the movement can become magnetised, which can result in the watch running generally much faster. The good news is, this is not a permanent state. If you feel your mechanical watch may have been affected by magnetism, your Rado Service Centre can use a special device to demagnetise your watch. This takes only a few seconds and, afterwards, your watch will work perfectly again.