Editorial disclosure: this guide was prepared for SuperReps by an administration-managed editorial profile. It is not a personal purchase or a first-hand product review.
A watch being “ten seconds fast” tells us very little unless we know when the measurement started. A short, consistent log gives the forum something concrete to work with.
Set up one reference
Choose one reliable clock and use it for the whole test. Record the watch’s offset at the start without repeatedly resetting it. If the seconds hand cannot be stopped, note the initial difference instead of forcing an exact match.
Record the same details each day
Use this format: date and time | offset in seconds | hours worn | overnight position | unusual events. Take readings at roughly the same time. Write down a stop, a winding change or a hard knock; do not silently remove an inconvenient reading.
Calculate the change, not just the offset
If the watch starts 8 seconds ahead and ends 20 seconds ahead after three days, it gained 12 seconds during the test: about 4 seconds per day. It did not gain 20 seconds per day. Treat a stopped watch as a break in the series and start a new segment.
Post the log, movement information if known, and what changed before the problem appeared. One daily reading cannot establish a cause or prove a service is needed. A sudden change deserves an inspection rather than a diagnosis from a single number.