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Time Duration Calculator

Calculate hours, minutes, and seconds between two clock times or the full duration between times on different dates.

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Time Between Two Times

ExampleSample values — edit any field to see your result.

Results update as you type.

Time Duration

9 hours, 0 minutes, and 0 seconds

Estimated result

Hours Component
9
Minutes Component
0
Seconds Component
0
Total Hours
9
Total Minutes
540
Total Seconds
32,400

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Compare scenarios

Keep a baseline, then change an assumption to see its effect side by side.

Time Duration9 hours, 0 minutes, and 0 seconds

Find the precise duration between two clock times or between times on two different dates. Results include a readable breakdown and totals in days, hours, minutes, and seconds.

Choose the right interval

What you knowUseExample
Two clock readings on one dayTwo Times8:30 AM to 5:30 PM = 9 hours
A shift crossing midnightTwo Dates10:45 PM to 2:15 AM the next day = 3 hours 30 minutes
Start and end timestamps several days apartTwo DatesSeptember 13 at 8:30 AM to September 15 at 5:30 PM = 2 days 9 hours

In Two Times, the result is the absolute difference between the clock readings. If the end reading is earlier, the calculator does not assume an overnight shift. Enter dates to make that direction explicit. If you want to add a duration such as 2 hours 30 minutes plus 45 minutes, use the Time Calculator instead.

Examples

8:30 AM to 5:30 PM

The duration is 9 hours, equal to 540 minutes or 32,400 seconds.

Two dated times

From September 13, 2026 at 8:30 AM to September 15 at 5:30 PM is 2 days and 9 hours, or 57 hours total.

Overnight shift

From September 13 at 10:45 PM to September 14 at 2:15 AM is 3 hours 30 minutes. Use Two Dates so the calculator knows the end is on the following day.

Formula

Each 12-hour clock entry is converted to seconds after midnight. Dated mode adds calendar-day difference × 86,400 before subtracting the start time.

For the overnight example, there are 1 hour 15 minutes from 10:45 PM to midnight and 2 hours 15 minutes from midnight to 2:15 AM. Their sum is 3 hours 30 minutes, or 12,600 seconds.

The dated calculation treats every calendar day as 24 hours and has no time zone. A daylight-saving clock change can make actual elapsed time differ by an hour.

Adult numeracy activity: read a shift record

This original practice activity focuses on choosing the correct dates, reading a 12-hour clock, and combining durations. It is an educational example, not a timesheet, payroll calculation, or statement of wage-and-hour rules.

RecordStartEnd
AMonday, 8:15 AMMonday, 4:45 PM
BTuesday, 10:45 PMWednesday, 2:15 AM
CThursday, 11:58:30 PMFriday, 12:17:15 AM

For each record, choose Two Dates, enter the stated start and end dates, and copy the duration before moving to the next row. Using dates matters for B and C: the end clock reading is earlier, but it occurs on the following day.

Learner prompts

  1. Which record lasts the longest? Estimate before calculating.
  2. Find each duration in hours, minutes, and seconds.
  3. Add the three durations. First combine whole hours, then minutes, then seconds; regroup whenever a unit reaches 60.
  4. A learner enters record B in Two Times and gets 20 hours 30 minutes. Why does that differ from the dated result?
  5. What additional information would be necessary before treating these records as paid working time?

Facilitator answer check

  • Record A is 8 hours 30 minutes.
  • Record B is 3 hours 30 minutes.
  • Record C is 18 minutes 45 seconds.
  • Together they total 12 hours 18 minutes 45 seconds.
  • Two Times finds the absolute difference between readings on one clock. It does not infer that 10:45 PM to 2:15 AM crosses midnight; Two Dates makes the next-day relationship explicit.

For the final prompt, examples include break periods, whether the record is a scheduled or actual time, rounding rules, and the applicable workplace policy. Those questions are deliberately outside this arithmetic tool.

Ask learners to explain the midnight crossing in words before using the calculator. A correct total with the wrong dates can hide a setup error.

Frequently asked questions

What is the difference between the two modes?
Two Times compares clock times on one day. Two Dates combines calendar dates with start and end times for durations spanning multiple days.
Are seconds supported?
Yes. Both modes accept hours, minutes, seconds, and AM or PM.
What happens when the time-only end is earlier?
The time-only mode reports the absolute clock-time difference. Use Two Dates when the interval crosses midnight so the dates make the direction explicit.
Does daylight saving time affect the result?
No. The dated mode measures calendar days plus clock time without attaching a geographic timezone.
How do I calculate an overnight duration?
Choose Two Dates and enter the actual start and end dates. For example, 10:45 PM on one date to 2:15 AM on the next is 3 hours 30 minutes. Two Times instead gives the absolute difference between two readings on one 12-hour clock, without assuming that the end is on the next day.

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