Date Difference Calculator
Days, weeks, months and working days between two dates — or add a duration to find a deadline.
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Days
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Weeks
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Months
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Working days
Detail
How to Calculate the Difference Between Two Dates
- Enter a start date and an end date.
- Read the total in days, weeks, months and years.
- Check the working-days figure if weekends matter.
- Switch to Add or subtract to work out a deadline instead.
- Copy the result.
Inclusive or exclusive? It changes the answer
From 1 January to 2 January is one day if you are measuring the gap, and two days if you are counting days. Both are correct, and which one a document means is rarely stated.
The distinction shows up in money. A hotel billing "2 nights" means the exclusive count. A contract giving "30 days' notice" usually means exclusive of the day of service. A holiday allowance covering "5 days" means inclusive of the first and last. This tool reports both, rather than picking one and letting you find out later which it chose.
Working days, and what this cannot know
The working-days figure counts Monday to Friday and skips weekends. It does not deduct public holidays, and it is worth being clear about why: they differ by country, by region within a country, and by year. Guessing yours would produce a number that looks authoritative and is wrong.
So for a deadline that genuinely depends on business days — a statutory response window, a settlement date — take the figure here and subtract the holidays from your own calendar. For most spans that is a handful of days, and the arithmetic is easier than the lookup.
A related trap in the Add mode: adding 30 working days is not the same as adding 42 calendar days, because the count depends on which weekday you start from. The tool walks the calendar day by day rather than multiplying.
Specifications
- Accepts
- No file needed
- Gives you
- On-screen result
- Where it runs
- Your browser — the file is never uploaded
- Sign-up
- None
- Cost
- Free, with no usage limits
FAQ
Does the count include both dates?
Both answers are given, because contracts and notice periods disagree about this. The plain difference is exclusive — 1 to 2 January is one day. The inclusive count treats both endpoints as days and gives two. Read which one your document means before relying on either.
How are working days counted?
Monday to Friday, excluding weekends. Public holidays are not deducted, because they differ by country and region and a wrong answer would be worse than none — check your own calendar for those.
Why do months and days not divide evenly?
Months are different lengths, so "3 months and 5 days" is calculated by walking the calendar rather than dividing. The total days figure is exact; the months-and-days breakdown is the human reading of the same gap.
Does it handle leap years?
Yes. Everything is computed from real calendar dates, so 29 February and leap years are handled by the date arithmetic rather than assumed away. Try 2024 — a leap year — against 2025 and the day counts differ by one.
Can I work out a deadline instead?
Yes — switch to Add or subtract. Give it a start date and a duration and it returns the resulting date, including a working-days mode for "30 business days from today".
Is my data sent anywhere?
No. All of this is date arithmetic in your browser. Nothing is uploaded, and the dates you enter are not recorded anywhere.