What is the accuracy of mechanical watches?

The accuracy of the mechanical watch is normally indicated as a "mean daily rate," which depends on the type of movement.

The accuracy of mechanical watches changes slightly day by day, depending on the various conditions in which the watch is used or the outside environment. Accordingly, the loss / gain of mechanical watches is not measured by a daily rate, but by an average of daily rates in one week or ten days when it is actually worn. This is why the accuracy of mechanical watches is indicated by "the mean daily rate."