Accuracy expectations: is -8 s/d acceptable on an entry-level automatic? · RWI-07751

Start with how you measured it. Comparing against a phone clock once a day for a week, at the same time, and noting the offset is reliable enough. One 24-hour reading isn't, because rate depends on wrist time, position overnight and state of wind. Average across several days before deciding anything.

One method that often helps without any service is using overnight resting position to cancel daily drift. Many watches gain in some positions and lose in others. If yours loses on the wrist, try leaving it crown up or dial up overnight and log the result for a few nights. Some people get close to zero this way.

Compare the observed rate with the exact caliber and cased-watch specification, if available. An example such as -8 seconds per day cannot be declared acceptable solely from its price category.