Time Duration Calculator
Find the time between two dates and times, or between two clock times past midnight, in days, hours, minutes and seconds, with total hours as a decimal.
Start
Today unless you pick another date.
End
Starts on tomorrow's date.
Add seconds
From Thu, Oct 22, 2026, 9:00 AM to Fri, Oct 23, 2026, 5:30 PM
1 day 8 hours 30 minutes
32.5 hours · 1,950 minutes · 117,000 seconds
| StartThu, Oct 22, 2026 · 09:00 | 9:00 AM |
|---|---|
| EndFri, Oct 23, 2026 · 17:30 | 5:30 PM |
| 1 day × 24 hours | 24:00:00 |
| End time minus start time | +8:30:00 |
| Duration (h:mm:ss) | 32:30:00 |
| In days, hours and minutes | 1 day 8 hours 30 minutes |
| Total hours (decimal) | 32.5 |
| Total minutes | 1,950 |
| Total seconds | 117,000 |
| In days (decimal) | 1.3542 |
How this is calculated
The calculator counts the whole days between the two dates, multiplies them by 24 hours, and adds the difference between the two clock times. From Thursday, October 22, 2026 at 9:00 AM to Friday, October 23 at 5:30 PM: 1 day × 24 hours = 24:00, plus 5:30 PM − 9:00 AM = 8:30, gives 32:30. That is 1 day 8 hours 30 minutes, or 32.5 hours.
If the end time of day is earlier than the start time, the difference is negative and is taken away: 10:00 PM on October 22 to 6:15 AM on October 24 is 48:00 − 15:45 = 32:15, which is 1 day 8 hours 15 minutes.
Decimal hours are the minutes divided by 60, added to the hours: 30 minutes is 0.5 hours, so 32 hours 30 minutes is 32.5 hours. Total minutes are the hours × 60 plus the minutes (1,950), and total seconds are the minutes × 60 (117,000).
With clock times only there is no date. If the end time is earlier than the start, the end is on the next day and 24 hours are added: 10:00 PM to 6:30 AM is 30:30 − 22:00 = 8 hours 30 minutes.
Daylight saving time
The result is clock time, read the way you would read a wall clock, in your own time zone. In most of the United States clocks jump from 2:00 AM to 3:00 AM on the second Sunday in March and go back from 2:00 AM to 1:00 AM on the first Sunday in November (15 U.S.C. § 260a). A span across the March change really lasts one hour less than the clock shows, a span across the November change one hour more.
Example: from 10:00 PM on Friday, October 30, 2026 to 6:00 AM on Sunday, November 1 is 32 hours on the clock, but 33 hours actually pass, because daylight saving time ends that night. When your span crosses a change, a note under the result gives both numbers. Arizona (except the Navajo Nation), Hawaii, Puerto Rico, Guam, the U.S. Virgin Islands and American Samoa do not change their clocks, so for them the clock time is the real time. The dates follow the rule in force since 2007. A time inside the skipped or repeated hour itself (such as 1:30 AM on the first Sunday in November, which happens twice) is ambiguous; work that out by hand.
Sources
Checked against the sources below on .
Questions people ask
How do I calculate the duration between two times?
Subtract the start time from the end time. If the end is earlier, add 24 hours to it first. 9:15 AM to 5:45 PM is 8 hours 30 minutes; 10:00 PM to 6:30 AM is 8 hours 30 minutes.
How many hours are between two dates and times?
Multiply the days between the dates by 24 and add the difference between the clock times. From 9:00 AM on October 22 to 5:30 PM on October 23, 2026 it is 24 + 8.5 = 32.5 hours.
How do I turn a time duration into decimal hours?
Divide the minutes by 60 and add them to the hours. 32 hours 30 minutes is 32.5 hours; 7 hours 45 minutes is 7.75 hours; 20 minutes is 0.33 hours.
How many minutes are in a duration?
Multiply the hours by 60 and add the minutes. 32 hours 30 minutes is 32 × 60 + 30 = 1,950 minutes, or 117,000 seconds.
Does daylight saving time change the duration?
On the clock, no; in real time, by one hour. A span across the November change lasts one hour longer, a span across the March change one hour shorter. The calculator shows clock time and adds a note with the real time when your span crosses a change.
How long is it from 11 PM to 7 AM?
8 hours. Add 24 hours to the end time and subtract the start: 31:00 − 23:00 = 8:00.