Time Duration Calculator: Hours Between Two Times
Use this time duration calculator to pick a start and an end date and time and see the time between them in days, hours, minutes and seconds, plus total hours. It handles overnight shifts and daylight saving, and it can add or subtract time too.
By Troopus · Updated: October 28, 2026
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- 🌙 Overnight and DST aware
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Time duration calculator: time between two times
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Times use your device time zone. Estimate for information only; for payroll or legal deadlines, check your own records and rules.
How do I calculate the time between two times?
Subtract the start time from the end time. This time duration calculator does it for you: enter a start and an end above and the result shows days, hours, minutes and seconds, plus the total in decimal hours. For example, 9:15 AM to 5:45 PM is 8 hours 30 minutes, or 8.5 hours.
By hand, convert both times to 24-hour format, subtract the hours, then subtract the minutes. If the end minutes are smaller than the start minutes, borrow one hour and add 60 minutes. With a date attached to each time, the calculator skips that step and works on the exact moments.
| Start | End | Duration | Decimal hours |
|---|---|---|---|
| 9:15 AM | 5:45 PM, same day | 8 hours 30 minutes | 8.5 |
| 7:50 AM | 12:20 PM, same day | 4 hours 30 minutes | 4.5 |
| 8:00 AM Monday | 2:30 PM Wednesday | 2 days 6 hours 30 minutes | 54.5 |
The result also gives total minutes and total seconds, which is handy for logs, video lengths and billing in small units. The "h:mm:ss" tile shows the same duration as a clock reading you can paste into a spreadsheet.
How do I calculate hours between two times overnight?
Put the end time on the next calendar day. A shift from 10:00 PM to 6:00 AM is 8 hours, because 10 PM to midnight is 2 hours and midnight to 6 AM is 6 more. Choose the end date one day later and the calculator counts across midnight correctly.
Tools that only ask for two clock times have to guess whether the end is on the same day. This one asks for dates as well, so there is nothing to guess. Tap the "Overnight" example to see a 10 PM to 6 AM shift filled in for you.
If you enter an end that is earlier than the start, the calculator does not stop with an error. It measures the gap backward and says so under the result, which is useful when you typed the two fields in the wrong order.
For a time card, open "More options" and enter an unpaid break in minutes. A 9:00 AM to 5:30 PM day with a 30 minute break shows 8 hours.
How do I add or subtract time?
Switch to "Add or subtract time", enter a start, choose Add or Subtract and type a duration such as 3h 45m, 1d 4h or 1:45. The result is the new date and time. For example, 2:30 PM plus 3 hours 45 minutes is 6:15 PM, and 8:00 AM minus 1 hour 20 minutes is 6:40 AM.
The duration box understands days (d), hours (h), minutes (m) and seconds (s), in any order, or the h:mm and h:mm:ss clock style. A bare number such as 90 is rejected on purpose, because it could mean minutes or hours.
| You type | Means |
|---|---|
| 2h 30m | 2 hours 30 minutes |
| 1d 4h | 1 day and 4 hours |
| 1:45 | 1 hour 45 minutes |
| 90 min | 90 minutes (1 hour 30 minutes) |
When you add days, the calculator moves the calendar date, so "1 day" keeps the same clock time even across a daylight saving change. Hours, minutes and seconds are added as real elapsed time.
How does daylight saving time change the result?
On a day when the clocks change, the clock-time gap and the real elapsed time differ by one hour. In US zones the clocks jump forward at 2:00 AM on the second Sunday of March, so 1:00 AM to 4:00 AM that night is only 2 hours. This calculator counts real elapsed time unless you tick "Ignore daylight saving changes".
The US rule is set by federal law: daylight saving time starts at 2:00 AM on the second Sunday of March and ends at 2:00 AM on the first Sunday of November. In 2026 those dates are March 8 and November 1.
| Start | End | Real time | Clock time only |
|---|---|---|---|
| Mar 8, 2026 1:00 AM | Mar 8, 2026 4:00 AM | 2 hours | 3 hours |
| Nov 1, 2026 12:00 AM | Nov 1, 2026 4:00 AM | 5 hours | 4 hours |
Use real time for anything physical, such as a worked shift or a flight. Use clock time only when you want the plain difference between two numbers on a wall clock. The "Clocks change" example fills in the March case. The answer you see depends on your device time zone: in a place without daylight saving, both views agree.
Can I use this time duration calculator as a time card calculator?
Yes, for one shift at a time. Enter the clock-in and clock-out times, subtract the unpaid break in minutes, then read the total hours. Decimal hours such as 7.5 are what most payroll systems want, and the result shows them next to the hours-and-minutes view so you can copy either one.
To total a week, calculate each day and add the decimal hours. The table shows how common minute amounts convert to decimals, which is the step people most often get wrong: 30 minutes is 0.5 hours, not 0.30.
| Minutes | Decimal hours |
|---|---|
| 6 | 0.1 |
| 10 | 0.1667 |
| 15 | 0.25 |
| 20 | 0.3333 |
| 30 | 0.5 |
| 45 | 0.75 |
Employers may round punches in ways set by their own policy and local wage rules, so use this as a check, not as a payroll record. If you need an overtime figure, try the time and a half calculator.
Frequently asked questions
How do I use a time difference calculator?
Enter the start and end date and time and read the result. By hand, convert to 24-hour time, subtract hours, then minutes, borrowing 60 minutes if needed. For example, 9:15 AM to 5:45 PM is 8 hours 30 minutes.
How many hours are between 10 PM and 6 AM?
There are 8 hours between 10 PM and 6 AM the next morning. Count 2 hours from 10 PM to midnight, then 6 hours from midnight to 6 AM. Set the end date to the following day in the calculator.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add them to the hours. For 8 hours 45 minutes, 45 divided by 60 is 0.75, so the total is 8.75 hours. The calculator shows total hours in decimals for you.
What is an elapsed time calculator?
An elapsed time calculator measures how much time passes between a start and an end, usually written as days, hours, minutes and seconds. It differs from clock time on days when daylight saving changes, because the clock jumps while real time does not.
How do I add 2 hours 30 minutes to a time?
Add the hours, then the minutes, and carry over any 60 minutes into an hour. For example, 4:45 PM plus 2 hours 30 minutes is 7:15 PM. In the calculator, use the Add or subtract time tab and type 2h 30m.
Does the calculator handle leap years and month lengths?
Yes. It works from exact calendar dates, so February 29 in leap years and months of different lengths are counted correctly. Days in the breakdown are blocks of 24 hours, so a result is never shown in months or years.
Which time zone does it use?
It uses the time zone of your device for both times. Daylight saving changes in that zone are included in the real elapsed time. To compare moments in two different zones, convert both to the same zone first.
Is my data sent anywhere?
No. The calculation runs in your browser. The dates and times you enter are not uploaded or stored, and the page makes no network requests while you use the tool.