Definition
Elapsed time
Elapsed time is how long an event lasts from a stated start time to a stated finish time.
What it means
Picture the day as a path. Put one finger on the start time, then move forward until the finish time. The distance you travel along that time path is the elapsed time. You can make convenient jumps—first to a whole hour, then to the finish—and add the jump lengths.
Remember it
Start → move forward through time → finish. Add the lengths of the jumps, not the clock labels.
Example
Film club starts at 9:35 and finishes at 10:20. Move 25 minutes from 9:35 to 10:00, then 20 minutes from 10:00 to 10:20. The elapsed time is 25 + 20 = 45 minutes.
Watch for
Clock readings are labels, not base-ten numbers. From 9:35 to 10:20 is not 85 minutes: after 9:59 the clock reaches 10:00, so the two forward jumps total 45 minutes.
Common mix-up
10:20 is the finish time; 45 minutes is the elapsed time. A clock time and a duration answer different questions.
Exact meaning
Elapsed time is the duration between a specified start time and a specified finish time, measured along one consistent time scale and expressed in time units.