Time Duration Calculator

Worked example

09:00 to 17:30 — 8.5 hours

Quick answer

Can the end time be after midnight?

Yes. If the end time is earlier than the start time, the calculator treats it as the following day.

What is the Time Duration Calculator?

Calculate elapsed time between two clock times, including overnight durations. Use it when you have the required inputs and want a deterministic, repeatable result with the calculation method visible.

How to use this calculator

Enter the values requested by the tool, keep units and time periods consistent, resolve any validation message, calculate, then review the primary answer together with the displayed formula and supporting values.

Formula and method

This calculator uses a deterministic formula and shows the calculation breakdown with the result so the answer can be checked.

Worked example

09:00 to 17:30 8.5 hours

Common mistakes to avoid

Check units, decimal points, percentages, signs, date/time order, selector choices, and rounding. For important decisions, verify the result against an independent source or qualified professional when appropriate.