Time Duration Calculator
Calculate the exact duration between a start and end time (same day or spanning days).
Calculate
Enter your values below.
Result
Duration
0
Total seconds
0
Formula used
Both start and end are combined into full timestamps, then the difference is broken into hours, minutes and seconds.
Example: 09:00 to 17:30 same day → duration = 8h 30m 0s.
How to use this calculator
- Enter Start date, Start time (HH:MM, 24h), End date, End time (HH:MM, 24h).
- Press Calculate to see your result instantly.
FAQ
Frequently asked questions
Can start and end be on different days?
Yes, enter different dates for a duration that spans midnight or multiple days.
What time format should I use?
24-hour format, like 09:00 or 17:30.
What if the end is before the start?
The duration is still shown as a positive value, treating the earlier point as the start.
Does this handle seconds precision?
The input is to the minute; the output breakdown includes seconds (always :00 from minute-level input).