Age Calculator
Find complete calendar years and months using end-of-month clamping, then count remaining UTC calendar days.
Open toolTime Duration Calculator
Subtract two 24-hour clock times; optionally move an earlier end time into the next day. Use HH:MM or HH:MM:SS.
Free to useNo sign-upRuns in your browser
Enter your details
Enter the inputs, then select Calculate duration.
Your result
Enter your details
Result will appear here
How Time Duration Calculator works
Subtract two 24-hour clock times; optionally move an earlier end time into the next day.
Use HH:MM or HH:MM:SS. Same clock times mean zero duration. Dates, time zones and daylight-saving changes are outside this clock-only calculation.
How to use Time Duration Calculator
Start with your own input.
Input and settings
Tool result
Run and check the output
Select Calculate duration. Review elapsed hours, minutes and seconds between clock times, then use Copy result or download the result file.
Review the details
When to use Time Duration Calculator
Measure a same-day time interval
To measure a same-day time interval, start with start clock time. Subtract two 24-hour clock times; optionally move an earlier end time into the next day.
Check an overnight shift
To check an overnight shift, start with start clock time. Use HH:MM or HH:MM:SS.
Convert a clock interval into decimal hours
To convert a clock interval into decimal hours, start with start clock time. Review elapsed hours, minutes and seconds between clock times, then use Copy result or download the result file.
How to read the result
Check what the output means.
Elapsed hours, minutes and seconds between clock times. Subtract two 24-hour clock times; optionally move an earlier end time into the next day.
Use HH:MM or HH:MM:SS. Same clock times mean zero duration. Dates, time zones and daylight-saving changes are outside this clock-only calculation.
Supported input and limits
Check the format before processing.
Use HH:MM or HH:MM:SS. Same clock times mean zero duration. Dates, time zones and daylight-saving changes are outside this clock-only calculation.
Inputs and results are handled in this browser.
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Open toolCalculate duration with your input
Review elapsed hours, minutes and seconds between clock times, then use Copy result or download the result file.
Time Duration Calculator: common questions
Answers about using Time Duration Calculator and understanding its results.
What does this tool support?
Use HH:MM or HH:MM:SS. Same clock times mean zero duration. Dates, time zones and daylight-saving changes are outside this clock-only calculation.
Can I save the result?
Yes. Download the result file after processing. Text results also have Copy result. Processing uses local browser code; no account is required.