Durations
Time duration calculator
Calculate elapsed hours and minutes between two clock times, including an overnight interval.
How to use this calculator
Enter Start hour (0–23), Start minute (0–59), End hour (0–23) and End minute (0–59). Calculate elapsed hours and minutes between two clock times, including an overnight interval. The answer updates when you change an input.
Understanding the result
This calculator compares clock times as a duration. It does not apply time zones or daylight-saving rules, and an earlier end time is treated as occurring on the following day.
Common questions
What assumptions does this result use?
Hours use a 24-hour clock. Equal start and end times represent zero elapsed time, not a full day.
Are intermediate values rounded?
No. The calculation retains JavaScript number precision internally and formats only the displayed result unless the stated method requires a discrete whole value.