Date & Time calculator
Time Duration Calculator
Calculate the duration between two times.
About the time duration calculator
The time duration calculator finds the hours and minutes between two times, including overnight spans.
How to use this calculator
- 1
Enter start time
Enter the start time in HHMM format (e.g., 900 for 9:00 AM).
- 2
Enter end time
Enter the end time. If end is before start, it assumes overnight.
- 3
View results
See the duration in hours and minutes.
How the calculation works
Converts times to minutes, finds the difference, and formats as hours and minutes. Handles overnight spans.
Example: 9:00 to 17:00 = 8 hours.
How date calculations work
Calendar math is trickier than it seems. Months have 28–31 days, leap years add an extra day every four years (except century years not divisible by 400), and time zones complicate exact hour counts. Our calculators use UTC-based date arithmetic to ensure consistent results regardless of your local time zone.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, market conditions, or individual circumstances. Results are for planning purposes only — consult a qualified professional for regulated, medical, financial, or construction decisions.
Frequently asked questions about time duration calculator
How accurate is the time duration calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.