Date Difference Calculator Calculators
Count the days, weeks and months between two dates.
Date Difference Calculator is a free online tool that count the days, weeks and months between two dates. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free — no account, no quota, no watermark
- Category
- Calculators
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- plain JavaScript
- Settings
- 3
- Works offline
- Yes, after the first visit
About Date Difference Calculator
Days are counted as calendar days, so daylight saving transitions do not shift the answer by one the way naive hour arithmetic does. The working-days figure excludes Saturdays and Sundays but knows nothing about public holidays, which vary by country and region.
How to use it
- Enter from, to and count both end dates.
- Results update the moment anything changes.
The 3 settings
| Setting | What it does | Default |
|---|---|---|
| From | Free text. | — |
| To | Free text. | — |
| Count both end dates | On or off. Off by default. | Off |
Under the hood
| Runs on | plain JavaScript — runs the whole thing |
| Controls | From, To, Count both end dates |
Questions
Should I count both end dates?
It depends on the question. For "how many nights in the hotel", no. For "how many days does the event run", yes. The tick box exists because both readings are legitimate and people mean different things.
Is the arithmetic exact?
It uses double-precision floating point — about 15 significant figures, far more than the inputs justify. Displayed rounding is cosmetic; the underlying numbers are not rounded between steps, so chained results do not drift.