Free tool · Time intervals
Time duration calculator
Find the hours, minutes, and seconds between two times. Choose the next day for an overnight interval, or enter dates for a longer span. Subtract breaks and add several intervals to get a total.
Enter 24-hour clock times as HH:MM or HH:MM:SS. Choose Next day when the end is after midnight.
Up to 31 intervals. Totals add every interval separately; overlapping entries are counted more than once.
Duration after breaks
08:00:00
Hours:minutes:seconds, including hours beyond 24.
- Decimal hours
- 8.0000
- Total minutes
- 480.0000
- Total seconds
- 28800
- Before breaks
- 08:00:00
- Breaks subtracted
- 00:00:00
Whole seconds are added before display rounding. Decimal hours and exported decimal totals use four places. Calculations stay in your browser.
This measures wall-clock differences in one unchanged time zone. It does not adjust for daylight-saving changes or travel between zones. Break deductions use your input and do not determine paid hours.
Method
How to calculate time between two times
Duration = end time − start time + day difference − breaks
09:00 to 17:00 is 8 hours. Subtract a 30-minute break to get 7 hours 30 minutes, or 7.5 decimal hours. For 22:00 to 06:00, choose Next day: the interval is eight hours.
Clock mode uses the same day or one calendar day later. Dates + times uses the explicit calendar dates. It compares the displayed clock values without applying a time zone or daylight-saving adjustment.
Examples
Hours and minutes between start and end
These examples use no break deductions and assume the clock does not change.
| Start | End | End day | Duration |
|---|---|---|---|
| 09:00 | 17:00 | Same day | 8h 00m |
| 09:58 | 13:57 | Same day | 3h 59m |
| 22:00 | 06:00 | Next day | 8h 00m |
| 08:00 | 08:00 | Next day | 24h 00m |
Common questions
Reading the interval
What if the end time is earlier than the start?
Choose Next day if the interval crosses midnight. The calculator asks you to make that choice rather than treating a mistyped earlier end as an overnight shift. Equal start and end times mean zero on the same day, or 24 hours on the next day.
How do I calculate more than 24 hours?
Choose Dates + times and enter both dates. For example, January 15 at 09:00 to January 17 at 10:30 in the same year is 49 hours 30 minutes. The result keeps the total hours instead of wrapping them into a clock time.
Does this handle daylight-saving time?
It measures the difference between wall-clock values. It does not determine actual elapsed time when clocks change or the endpoints use different time zones. Those cases need dated, zone-aware timestamps. Invalid calendar dates are rejected.
Can I total several intervals?
Yes. Add up to 31 entries, with a separate break deduction for each. The total adds valid whole-second results before rounding. Overlapping entries count separately; this tool does not merge them. Fix invalid entries before copying or exporting the full result.
How is this different from the other time tools?
Use this page when you know both endpoints. If you know the start and a target work duration, use the 8 hour shift calculator to find the end. To convert a duration you already know, use the time to decimal calculator.