Answer first
What this calculator tells you
Calculate the hours and minutes between two times of day, including across midnight. Find out how long a shift, a drive or a task ran without doing the subtraction by hand. Formula: Duration = end time − start time, adding 24 hours when the end is earlier than the start. At the worked-example inputs, the hours between is 8.25. Holding every other input steady, moving start time from 7:30 AM to 9:30 AM moves the result from 7.25 to 9.25.
Transparent method
The formula
Find out how long a shift, a drive or a task ran without doing the subtraction by hand.
Worked example
Example inputs
How to interpret the result
The gap between two times looks like simple subtraction until the range crosses midnight. From 8:30 AM to 4:45 PM the answer is 8 hours and 15 minutes, or 8.25 hours. From 10:00 PM to 2:00 AM the clock numbers say a negative four hours, but the real gap is four hours forward, so the page adds a day whenever the end is earlier than the start.
Times are worked out from the clock readings you enter, to the minute. Daylight saving, leap seconds and a workplace's own rounding or break rules apply only where a field asks for them, so confirm any pay, travel or scheduling decision against the official clock and your own policy.
Before you rely on it
What to check
Use this for spans of less than 24 hours. Two identical times read as no time at all, not as a full day.
The common error
Where people go wrong with time duration calculator
Subtracting the hour numbers only. That ignores the minutes and gives 8 hours for a span that is really 8 hours and 15 minutes.
Sensitivity evidence
How start time changes the hours between
Holding every other input at the worked-example value, moving start time from 7:30 AM to 9:30 AM moves the hours between from 7.25 to 9.25: a spread of 2.00, or 24% of the worked-example result.
| Start time | Hours between | Minutes between |
|---|---|---|
| 7:30 AM | 9.25 | 555 |
| 8:00 AM | 8.75 | 525 |
| 8:30 AMworked example | 8.25 | 495 |
| 9:00 AM | 7.75 | 465 |
| 9:30 AM | 7.25 | 435 |
Two variables at once
Hours between by start time and end time
Across the grid the hours between runs from 6.25 to 10.25. Moving start time from 7:30 AM to 9:30 AM shifts it by 2.00 at the middle column, and moving end time from 3:45 PM to 5:45 PM shifts it by 2.00 at the middle row, so neither is the bigger lever here.
| Start time \ End time | 3:45 PM | 4:45 PM | 5:45 PM |
|---|---|---|---|
| 7:30 AM | 8.25 | 9.25 | 10.25 |
| 8:00 AM | 7.75 | 8.75 | 9.75 |
| 8:30 AM | 7.25 | 8.25 | 9.25 |
| 9:00 AM | 6.75 | 7.75 | 8.75 |
| 9:30 AM | 6.25 | 7.25 | 8.25 |
The highlighted cell is the worked example: 8.25.
Step by step
The worked example, input by input
| Input | Value used | What it means |
|---|---|---|
| Start time | 8:30 AM | Enter the start time used in this calculation. |
| End time | 4:45 PM | Enter the end time used in this calculation. |
| Hours between | 8.25 | |
| Minutes between | 495 | |
Inputs, definitions and assumptions
Start time
Enter the start time used in this calculation. The prefilled worked-example value is 8:30 AM.
End time
Enter the end time used in this calculation. The prefilled worked-example value is 4:45 PM.
How to use this calculator
- 1Verify the inputs. Gather start time and end time from your own documents; the prefilled values are examples.
- 2Save a baseline. The worked example puts the hours between at 8.25. Store your own version of it as Scenario A.
- 3Test one change. Change one assumption at a time so the driver stays visible.
- 4Check the boundary. Read the interpretation boundary above before acting on the result.
People also ask
Frequently asked questions
How do you calculate time duration?
Duration = end time − start time, adding 24 hours when the end is earlier than the start. At the worked-example inputs the hours between is 8.25.
What does the time duration result mean?
Find out how long a shift, a drive or a task ran without doing the subtraction by hand.
How much does start time change the hours between?
Holding every other input at the worked-example value, moving start time from 7:30 AM to 9:30 AM moves the hours between from 7.25 to 9.25, a spread of 2.00.
What are the limits of this time duration calculator?
Times are worked out from the clock readings you enter, to the minute. Daylight saving, leap seconds and a workplace's own rounding or break rules apply only where a field asks for them, so confirm any pay, travel or scheduling decision against the official clock and your own policy. The tables on this page test start time only from 7:30 AM to 9:30 AM; a value outside that range is not tabulated here.
Does the calculator account for daylight saving time?
Only where a field asks for it. The time zone calculator has a daylight saving setting for each zone. The other tools work from the clock times you enter, so enter the local clock reading as it appears on the day.
What happens when a time range crosses midnight?
The tools add 24 hours when the end time is earlier than the start, so 10:00 PM to 6:00 AM is eight hours. Two identical times read as zero, not as a full day.
Why do payroll systems use decimal hours?
Multiplying a rate by 7.75 is simple, while multiplying by 7 hours 45 minutes is not. Decimal hours turn a clock duration into a plain number that a spreadsheet can total.
Is 12 AM midnight or noon?
Midnight. 12 AM is the start of the day, 00:00 on the 24-hour clock, and 12 PM is noon, 12:00. Writing 12:00 midnight or 12:00 noon avoids doubt in a schedule.
Why do two time zone converters sometimes disagree?
Usually because one has applied daylight saving and the other has not. Regions change their clocks on different dates, so check the date you are converting for.
Sources and evidence
Free Calculators Online is independent and is not affiliated with or endorsed by the source organizations. Educational estimates only.