How to use the Time Duration Calculator
This tool finds the time between a start and end date and time.
Open the Time Duration Calculator →
What you need to enter
- Start date
- Start time
- End date
- End time
The formula
Duration = end − start, shown in days, hours, minutes and decimal hours.
Worked example
Using the default values in the calculator:
- Start date: 2026-10-13
- Start time: 09:00
- End date: 2026-10-13
- End time: 17:30
| Duration | 0 d 8 h 30 min |
| Total hours | 8.5 |
| Total minutes | 510 |
Tips for better results
- Use 24-hour times to avoid AM/PM mistakes.
- Time zones are not applied.
Common mistakes to avoid
- Mixing time zones.
- Crossing midnight without changing the date.
Please note: Results are estimates for general use. For safety-critical work such as electrical or building projects, check with a qualified professional and local codes. See our Disclaimer.