Official Seiko statement

Shocks: Your watch is a precision measuring instrument. Treat it carefully, and it will serve you well. Avoid undue shocks (such as dropping on hard surfaces). The normal shocks caused by sports like tennis or golf present no threat, but “Twin Seiko” (extra-high precision) watches should not be worn while participating in such sports.

Perspiration: You should aim to protect your watch from heavy perspiration. Please remember to wipe it dry as soon as conveniently possible.

Temperature Extremes: Quartz watches are much less affected by extremes of temperature than mechanical watches, and are designed to keep good time if worn on the wrist for eight hours a day with ambient temperatures between -10°C and +35°C. If removed completely from the wrist, your watch may lose time during the winter, but will return to normal accuracy as soon as you start wearing it again.

If your watch is stored at temperatures outside the normal range (as low as -10°C or as high as +60°C) the electronic components may cease to function normally.

The response time of liquid crystals used in the displays on digital watches at temperatures below freezing is slow, and they tend to look very dark at high temperatures, but normal performance returns at normal temperatures.

Battery life can be significantly reduced at high temperatures (above 40°C), and battery fluid may even leak out.

Chemicals: Chemical substances, gases, mercury, etc., may change the color of cases, bracelets and straps. Mercury (for instance, from a broken thermometer) can cause particularly unsightly grey discoloration of gold plating.

Case and band: Metal bracelets should be washed carefully in water. If really dirty, use a soft toothbrush with soap and water to brush away the dirt. Finally, rinse with water and dry carefully with a soft cloth. If your watch is not water resistant, be careful not to get water on the case. Cases should be wiped gently with a slightly moistened soft cloth and then dried carefully.

Leather straps should be slightly loosened in the summer, when they may absorb perspiration. A tight strap not only prevents the passage of air over the strap undersurface but can also cause a perspiration rash on the wrist.

If the strap ever becomes wet with perspiration, wipe it dry with a soft cloth.

When you take off your watch, leave it in a well-ventilated spot. Never put it in a sealed container when it is still damp with perspiration.

Avoid leaving your watch in direct sunlight. The strap color may fade.