Generally speaking, the daily error of a quartz watch is about ±0.5 seconds, and the daily error of a mechanical watch is about ±30 seconds. If it is a better movement, such as an observatory-certified movement, the error is -4/+6 seconds per day. For example, watch brands that use controle officiel suisse des chronometres movements include Mido, Omega, Rolex, etc..

The requirements of the controle officiel suisse des chronometres movement are very strict. The current error standard is -4/+6 seconds. Although the controle officiel suisse des chronometres is very accurate, there are still higher standards. For example, some famous watch brands have their own standards, such as  Rolex watches with the words "Superlative Chronometer Officially Certified" are all within -2/+2 seconds per day. There is also the PP mark of the top watch Patek Philippe, and the accuracy requirement is -3/+2 seconds/day.

For example, we often see that the watch parameters are written as waterproof to 30 meters, which does not mean that you can dive to a depth of 30 meters while wearing the watch. Generally speaking, a 30-meter (3ATM, that is, 3 atmospheres) waterproof watch can only be used for daily grooming or use in the rain, that is, water droplets only splash on the surface without any water pressure applied to the watch. If you want to swim or dive, it is recommended to have at least 100 meters of water resistance or above.

All watches are not resistant to hot water, be sure not to wear a watch in a hot bath or sauna, otherwise it will cause damage to the watch.

The automatic mechanical watch is not completely automatic, it relies on the swing of the human arm, through the continuous swing of the rotating heavy hammer on the watch movement to drive the mainspring to be tight and achieve the purpose of automatic winding. If you don't exercise enough or stop, you still need to rewind the string manually.