Time Duration Calculator
Calculate the exact time between two times or dates in hours, minutes, and seconds. Get elapsed time, total minutes, decimal hours, and more instantly in your browser.
Calculate elapsed time
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How Many Hours Are Between Two Times?
Subtract the start clock from the end clock. 9:00 AM to 5:00 PM is 8 hours. 8:00 AM to 4:00 PM is the same 8-hour span. If you need minutes, 9:15 AM to 5:45 PM is 8 hours 30 minutes.
When the end time is earlier, the span crosses midnight. 10:00 PM to 6:00 AM is not a negative number. Add 24 hours to the clock difference, and the duration is 8 hours. A meeting, a work shift, a study block, or a drive uses the same rule: start, end, and the elapsed time between them.
How to Use the Time Duration Calculator
- Choose times or dates. Stay on Between Two Times for a clock span, including an overnight shift. Use Between Dates & Times when the start and end are on different days.
- Enter the start and end. Type the hour, minute, and second. The default clock is 12-hour AM/PM. Switch to 24-hour if you already have times like 17:00.
- Mark the next day when you need it. If the end clock is earlier than the start, the span is counted as the next day. Turn on End time is next day when the end clock is later but still belongs to the following day.
- Read the elapsed time. The main line is the duration in days, hours, minutes, and seconds. Decimal hours, total minutes, and total seconds stay visible underneath.
How Time Duration Is Calculated
For two clock times, convert each time to minutes past midnight. Hours and seconds are included the same way, in seconds, so the displayed hours and minutes do not come from a rounded float.
Start minutes = start hour × 60 + start minute. End minutes = end hour × 60 + end minute. Duration = end − start.
If the interval crosses midnight, duration = end − start + 1,440. Decimal hours = total minutes ÷ 60. Total seconds = total minutes × 60. With leftover seconds, the totals use the exact second count instead of dropping them.
For two dates and times, duration = end timestamp − start timestamp. That difference becomes days, hours, minutes, seconds, total hours, decimal hours, total minutes, and total seconds. A leap day and a month boundary are just part of the timestamp. Daylight saving is included only in this date mode, because it changes the local clock.
Time Duration Examples
| Span | Duration | Decimal hours |
|---|---|---|
| 9:00 AM → 5:00 PM | 8 hours | 8.00 |
| 8:30 AM → 5:15 PM | 8 hours 45 minutes | 8.75 |
| 10:00 PM → 6:00 AM | 8 hours | 8.00 |
| 9:15 AM → 12:45 PM | 3 hours 30 minutes | 3.50 |
| Mar 1, 2026 9:00 AM → Mar 3, 2026 5:30 PM | 2 days 8 hours 30 minutes | 56.50 |
The last row is a multi-day timestamp: two full days from March 1 at 9:00 AM to March 3 at 9:00 AM, plus 8 hours 30 minutes, which is 2 days 8 hours 30 minutes.
What Can You Calculate With This Tool?
- The time difference between a start and an end, in one readable line.
- Elapsed time for a meeting, a study session, a shift, or a trip.
- Hours between two times, minutes between two times, and the seconds when you enter them.
- An overnight duration, such as a 10:00 PM to 6:00 AM shift.
- A multi-day timestamp duration when the start and end fall on different dates.
It does not deduct a lunch break or build a weekly timesheet. For that, calculate net work hours. To move a clock forward or backward, add or subtract time from a starting time.
Common Time Duration Mistakes
- AM and PM. 5:00 without PM is 5:00 AM. A 9:00 AM to 5:00 AM result is an overnight span, not an 8-hour workday.
- Overnight spans. An earlier end time is the next day, not a negative duration. 11:59 PM to 12:01 AM is 2 minutes.
- Decimal hours. 8 hours 30 minutes is 8.50 hours, not 8.30. Thirty minutes is half an hour.
- Dates versus timestamps. Whole days between calendar dates, with no clock, belong on the date calculator. This page keeps the time of day.
- Daylight saving and time zones. Clock mode ignores the missing or repeated hour. Date mode follows the local device clock. To show the same moment in another city, convert time between time zones first.
Time Duration Calculator vs Other Time Tools
| Need | Recommended tool |
|---|---|
| Time between times | Time Duration Calculator |
| Add or subtract time | Time Calculator |
| Hours worked and breaks | Work Hours Calculator |
| Days between dates | Date Calculator |
| Time zone conversion | Time Zone Converter |
A decimal-hour total from two clocks also lives on the hours calculator. Use this page when you want the full elapsed time, including minutes and seconds.
Frequently Asked Questions
What is a time duration calculator?
It measures the elapsed time from a start to an end. You can use two clock times, including an overnight span, or two dates with times. The result is shown in hours, minutes, and seconds, plus decimal hours and totals.
How do I calculate the time between two times?
Convert both clocks to minutes past midnight, then subtract the start from the end. If the end is earlier, add 1,440 minutes so the span crosses midnight. 9:00 AM to 5:00 PM is 480 minutes, which is 8 hours.
How many hours are between 9 AM and 5 PM?
8 hours. That is 480 minutes, 28,800 seconds, and 8.00 decimal hours. A 9:00 AM to 5:30 PM span is 8 hours 30 minutes, or 8.50 decimal hours.
Does the calculator handle overnight times?
Yes. 10:00 PM to 6:00 AM is 8 hours. The end is earlier on the clock, so it is counted as the next day instead of a negative number. Use End time is next day when you want that extra day even if the end clock looks later.
How do I calculate minutes between two times?
Use the same subtraction, then read Total minutes. 9:15 AM to 5:45 PM is 510 minutes. If the span includes seconds, the minute total keeps the fraction, and Total seconds stays exact.
Can I calculate elapsed time between two dates?
Yes. Switch to Between Dates & Times and enter both dates and times. The duration is the end timestamp minus the start timestamp, so a multi-day span, a month change, and a leap day are included.
How are decimal hours calculated?
Decimal hours = total seconds ÷ 3,600. 8 hours 30 minutes is 30,600 seconds, which is 8.50 decimal hours. The hours-and-minutes line stays exact; the decimal is only the same span written as one number.
Does daylight saving time affect time duration?
Between Two Times uses the clock, so 10:00 PM to 6:00 AM is 8 hours even on a daylight-saving night. Between Dates & Times uses your device’s local timestamps, so a spring-forward or fall-back in that span changes the elapsed time.
Is this calculator free?
Yes. It runs in the browser with no account and no charge.
Are my time entries uploaded?
No. The calculation runs on your device. A share link you create puts the times in the address, and this browser can remember the last entry. Nothing is uploaded to EverydayTools.
Related Tools
- Time CalculatorAdd or subtract time from a starting time.
- Hours CalculatorTurn a span into a decimal-hour total.
- Work Hours CalculatorCalculate hours worked and breaks, then net work hours.
- Date CalculatorCalculate days between dates, without clock times.
- Time Zone ConverterConvert time between time zones.