Keep time and record laps
Choose Start, then Lap whenever you want a split. Pause stops adding time, and Resume continues. Reset is available while paused.
Laps recorded at 10 and 25 seconds have durations of 10 seconds and 15 seconds. Their cumulative totals are 10 seconds and 25 seconds. Copy laps before leaving if you want to keep them.
How timing works
Elapsed time comes from the browser’s monotonic clock, so a delayed screen update does not itself lose time. Displayed hundredths are not a guarantee of precision. Sleep and browser page cleanup can interrupt the watch.
For a shift between two clock times, use the Hours calculator.