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WGX

Time Duration Calculator

Measure the time between two dates, down to the minute.

Start
End

Times are optional. Leave them blank to count whole days.

DurationExample

3d 4h 30m

76.50 total hours

0 minutes

Total minutes
0

What this measures

The distance between two moments on the calendar: how long a job ran, how long until a deadline, how long a shipment took. It handles spans of any length, across month ends, year ends and leap days.

For two times on a single day, the Work Hours Calculator is quicker — two fields and an optional break. To add several durations together, use the Time Calculator.

A worked example

A job that starts on 3 March at 09:00 and finishes on 7 March at 14:30:

  • 3 March 09:00 to 7 March 09:00 is 4 whole days.
  • 09:00 to 14:30 adds 5 hours 30 minutes.
  • The span is 4 days 5 hours 30 minutes.
  • As a total: 101.5 hours, or 6,090 minutes.

Where counting by hand goes wrong

Two places, reliably. The first is a month end: going from 31 January to 2 February is two days, but the day numbers suggest otherwise, and February is the month where the answer also depends on the year. The second is borrowing — when the end time is earlier in the day than the start time, a day has to be given back before the hours can be subtracted. That is where "4 days 5 hours" quietly becomes "5 days minus something".

Time zones and daylight saving

This tool ignores both, on purpose. Both moments are treated as wall-clock values, so the answer is what a calendar and a clock say. On the day clocks move forward, a span from noon to noon still reads as 24 hours here, even though only 23 hours of real time passed.

That is what people usually mean. If you need elapsed physical time across a clock change or between time zones — for flight times, or scientific measurement — this is the wrong tool, and it will be out by the size of the clock change or the difference between the zones.

Why the answer is in days, not months

A month has no fixed length. One month after 31 January could reasonably be 28 February, 2 March or 3 March, and every answer using months inherits that ambiguity. Days do not have the problem, so long spans are given in days — 400 days rather than "1 year, 1 month and a bit".

Common uses

  • How long a task, job or process actually took.
  • How long until a deadline or an event.
  • How long something has been running, in days.
  • Billing a span that crosses midnight or several days.

Questions

How do I work out the time between two dates and times?

Enter both moments above. From 3 March at 09:00 to 7 March at 14:30 is 4 days 5 hours 30 minutes, or 101.5 hours. Counting by hand goes wrong in two places: crossing a month end, and borrowing an hour when the end time is earlier than the start time.

Can I use it for two times on the same day?

Yes — enter the same date twice. If that is all you need, the Work Hours Calculator is quicker, because it asks for two times and nothing else, and it can subtract an unpaid break.

What if I leave the times blank?

Both count as midnight, so two dates alone give whole days. 3 March to 7 March is 4 days.

Does it handle daylight saving?

It ignores it deliberately. Both moments are treated as wall-clock values, so a span across a clock change reads as the clock reads it. A day is 24 hours here, even the day the clocks move — which is what people mean when they ask how long something took.

Why does it not answer in months or years?

Because months have no fixed length. "One month" from 31 January is ambiguous, and any answer using it would be too. Days are unambiguous, so long spans are given in days.

Why does entering an end before the start show an error?

Because the dates are explicit, so there is nothing to infer. A shift entered as 22:00 to 06:00 with no date is obviously overnight; 7 March to 3 March is a mistake, and quietly reversing it would hide a wrong entry.

Is anything I enter sent anywhere?

No. The arithmetic runs in your browser. Nothing you type is transmitted, stored or logged.