Time Difference Calculator
Find the duration between a start time and an end time, including intervals that cross midnight.
A time difference calculator measures elapsed time between two clock times. It is useful for work shifts, appointments, travel, classes, calls, workouts and other schedules where you need to know how long an interval lasts.
Enter a start time and an end time, then calculate. If the end time is earlier than the start time, the calculator treats the interval as crossing midnight.
This calculator measures clock-time duration within a 24-hour cycle. For intervals spanning multiple calendar days, use the date calculators or enter the duration directly.
This tool also fits into a wider set of practical utilities. Depending on what you are trying to calculate or measure next, you can continue with Time Calculator, Time Addition Calculator, Time Subtraction Calculator, online stopwatch and 30 minute timer. For the complete collection, visit the utility tools homepage and choose another tool when your task changes.
How to use this calculator
- Enter your values. Select the dates or numbers required by the calculator.
- Check the inputs. Make sure the dates are in the order and range you intend to calculate.
- Calculate the result. The result appears instantly in the calculator above without submitting a form.
- Use the result. Apply the result to your schedule, deadline, planning or date calculation.
How the calculation works
This calculator measures clock-time duration within a 24-hour cycle. For intervals spanning multiple calendar days, use the date calculators or enter the duration directly. The calculation is performed locally in your browser, so the page can return a result immediately after you change the inputs.
Things to know about date calculations
Calendar calculations can differ depending on whether a result is treated as an elapsed interval or an inclusive count. This site uses clear calendar-date rules and explains important assumptions where they affect the result. Business-day calculations on this page exclude weekends but do not automatically remove public holidays.
Frequently asked questions
How do I calculate the difference between two times?
Enter the start and end times and calculate the elapsed duration between them.
Can it calculate an overnight shift?
Yes. When the end time is earlier than the start time, the calculator treats the end time as occurring on the following day.
Does it include seconds?
Yes. You can enter hours, minutes and seconds for both times.