The allowable error range of the mechanical watch is ± 45 seconds / day. The average error range of the movement certified by the observatory is between -4 seconds / day and +6 seconds / day. The specific error depends on the movement used by the watch.
Not according to the principle that the higher the price is, the smaller the error is, the power source of the automatic mechanical watch is that the swing of the wearer’s wrist generates energy to wind the mainspring. A fully wound automatic mens watch can continue to run for about 35 hours: if it is guaranteed to be worn daily Under the circumstances, it can be operated for about 15 hours.
If it is not worn for more than the above time or the swing is insufficient (the wearer has little exercise), the watch will stop. It is recommended that you wind the watch before wearing it again.