Does it handle daylight saving time?

Yes. JavaScript's Date handles DST internally, so a span that crosses a 'spring forward' is one hour shorter, and a 'fall back' is one hour longer - just like the real elapsed time.

How is 'business hours' computed?

We count whole hours within a configurable working window (default 09:00-17:00, Monday-Friday). Holidays aren't subtracted - that's a country-specific concept.

Time Duration Calculator

How many hours, minutes or seconds between two times - or two full datetimes - in your browser.

Runs in your browser

Two pickers: a start datetime and an end datetime. We compute the duration and show it in three forms - HH:MM:SS, total seconds, and a friendly 'X days Y hours Z minutes' breakdown. Crosses midnight, day boundaries and timezones (uses your local timezone).

Start

End

Invalid date range

How to use it

Pick the start and end
Date + time pickers for both. Default is the current moment for both, edit to suit.
Pick the breakdown style
HH:MM:SS, total seconds, or natural language.
Copy the result
All three breakdowns are shown; copy the one you need.

What is it?

A duration calculator is a stopwatch you can wind backwards: tell it when something started and when it ended, get the elapsed time. The arithmetic is trivial once both endpoints are normalised to a UTC millisecond timestamp; the user-facing complication is the breakdown - hours, minutes, seconds, days, optionally business hours - and the parsing of the input picker.

When to use it

Working out billable hours from a timesheet's clock-in and clock-out columns. Comparing two shift lengths to spot the longer one. Verifying that an SLA window (9 a.m. to 5 p.m. business hours) was met. Counting the elapsed time of a flight, a meeting or a cooking session.

Common mistakes

Forgetting that the 'end before start' case happens (use absolute value or assume the user typoed). Mixing up 'business hours' with 'wall-clock hours' for events that cross overnight. And confusing 'minutes' (decimal minutes - 1.5 = 1m30s) with 'hours and minutes' notation.

FAQ

Does it handle daylight saving time?: Yes. JavaScript's Date handles DST internally, so a span that crosses a 'spring forward' is one hour shorter, and a 'fall back' is one hour longer - just like the real elapsed time.
How is 'business hours' computed?: We count whole hours within a configurable working window (default 09:00-17:00, Monday-Friday). Holidays aren't subtracted - that's a country-specific concept.

Date Calculator

Days between dates, add or subtract days, business-day count.

Unix Timestamp Converter

Convert between Unix epoch (seconds or milliseconds) and human-readable date / time, in UTC and local.

Pace Calculator

Running pace, distance and time - any two, get the third. Splits in km and miles.