Speedy Calculator

Time Difference Calculator

Everyday Life Updated October 25, 2026

Quick answer

The time difference calculator finds the exact time between two dates and times – optionally in different time zones – in days, hours and minutes, total hours, minutes and seconds.

h
Time difference
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Days
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and hours
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and minutes
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Total hours
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Total minutes
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Total seconds
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Comparing times across time zones – for flights, calls or deadlines – means converting both to the same zone first. A flight leaving London at 10:00 and landing in New York at 13:00 the same day (5 hours behind) takes 8 hours.

How to use the Time Difference Calculator

  1. Start date
  2. Start time
  3. End date
  4. End time
  5. End time zone ahead of start by

Results update as you type, and every field accepts the units shown in its menu.

How it works

Enter the start date and time, the end date and time, and – if they are in different time zones – how many hours the end zone is ahead (negative if behind).

Tips

  • Check whether the end date should be included – event durations usually include it, elapsed time does not.
  • Months have 28–31 days, so “one month” is counted by calendar date, not as 30 days.
  • Use 24-hour time or set AM/PM carefully when entering clock times.
  • Time zones and daylight-saving changes are not applied unless the calculator says so.

Common mistakes to avoid

  • Counting a 30-day month when a calendar month is meant (or the reverse).
  • Forgetting leap years when counting days across February.
  • Mixing decimal hours (7.5 h) with clock time (7:30).

Inputs explained

Field What to enter
Start date A date
Start time A clock time (hours and minutes)
End date A date
End time A clock time (hours and minutes)
End time zone ahead of start by In h

What each result means

  • Time difference = [Difference in hours]
  • Days = sign([Difference in hours])×floor(abs([Difference in hours])÷24)
  • and hours = sign([Difference in hours])×floor(mod(abs([Difference in hours]), 24))
  • and minutes = sign([Difference in hours])×round(mod(abs([Difference in hours])×60, 60))
  • Total hours = [Difference in hours]
  • Total minutes = [Difference in hours]×60
  • Total seconds = [Difference in hours]×3600

Formula

Difference = (end date + end time − zone offset) − (start date + start time)Zone offset = how many hours the end time's zone is ahead of the start time's zone

Worked example

Inputs — Start date: 2026-10-25; Start time: 10:00; End date: 2026-10-25; End time: 13:00; End time zone ahead of start by: -5 h.
Results — Time difference = 8 h 0 min; Days = 0; and hours = 8; and minutes = 0; Total hours = 8; Total minutes = 480; Total seconds = 28,800.

Frequently asked questions

How do I find the time difference between two times?

Subtract the start from the end; add 24 hours for each day in between.

How do I handle time zones?

Convert both times to the same zone – subtract the end zone's offset relative to the start.

How long is a flight from 10:00 London to 13:00 New York?

8 hours (New York is 5 hours behind).

What formula does the Time Difference Calculator use?

Difference = (end date + end time − zone offset) − (start date + start time).

Cite this calculator

Speedy Calculator. (2026). Time Difference Calculator. Speedy Calculator. https://speedycalculator.com/calculators/everyday-life/time-difference/