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Date & time

Time Duration Calculator

Find elapsed wall-clock hours and minutes between two times, including an overnight interval.

Date conventions explained belowClear start and end values

Set your dates & time

Runs on your device

TIME SUMMARY

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter start hour (24-hour), start minute, end hour (24-hour), end minute, end time occurs.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

Convert each time to minutes after midnight and subtract start from end. Add 1,440 minutes when the end is on the next day. Divide total minutes by 60 for decimal hours.

A WORKED EXAMPLE

09:30 to 17:00 on the same day is 7:30, or 7.5 decimal hours. 23:00 to 01:00 on the next day is 2:00.

What to keep in mind

This is wall-clock arithmetic without time zones, daylight saving changes or seconds. It does not subtract breaks. Use the next-day option explicitly for overnight intervals.

Common questions

Is 7:30 the same as 7.30 decimal hours?

No. Thirty minutes is half an hour, so 7:30 is 7.5 decimal hours.

What happens if start and end times match?

Same day gives zero hours. Next day gives 24 hours.

Methodology maintained by ClarityKit. How these tools are built and checked.