Time Duration Calculator Between Two Times and Dates
Calculate how much time passes between a start date-time and an end date-time. Use it for work shifts, event schedules, logs, overnight ranges, and date duration checks.
A time duration between two times is the end date-time minus the start date-time.
For overnight ranges, make the end date the next day.
Use complete start and end values
A date plus a time removes ambiguity for overnight and multi-day ranges.
Keep time zones separate
This calculator uses the local time from your browser. Convert time zones first if the endpoints are in different regions.
duration = end date-time - start date-time
Total hours, minutes, seconds, and days are derived from the same millisecond difference.
Use this page for questions like how many hours are between 9 AM and 5:30 PM, or how long a range lasts between two dates and times.
Use the add/subtract page when you already have elapsed durations and want to combine them.
Example
09:00 to 17:30 on the same date is 8 hours 30 minutes.
Assumption
The selected dates and times are interpreted in the local time zone from your browser.
Limitation
This page does not apply timesheet break rules, payroll rounding, holidays, or cross-time-zone conversion.
Work shifts
Calculate hours between a start and end shift time.
Overnight ranges
Set the end date to tomorrow when the range crosses midnight.
Event schedules
Find total duration for sessions, launches, classes, or appointments.
Log cleanup
Convert timestamp ranges into human-readable elapsed time.
What is a time duration calculator?
A time duration calculator finds the elapsed time between a start and end value. This page supports local dates and times so it can handle same-day, overnight, and multi-day ranges.
How do I calculate hours between two times?
Enter the same start and end date, then choose the two times. The total hours field shows the duration as a decimal hour value.
How do I calculate an overnight shift?
Use today's date for the start and tomorrow's date for the end. For example, 22:00 today to 06:00 tomorrow returns 8 hours.
Can the result be negative?
Yes. If the end date-time is before the start date-time, the calculator shows a negative duration.
Does this calculate business days?
No. Use the business days calculator when you need weekdays, weekends, or excluded holiday dates.
Suggested workflow
Time range planning path
Calculate a start-to-end duration, then refine the same plan with business-day, unit, or time-zone tools.