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Date Calculator
Days between dates, or add and subtract from a date.
100% FreeRuns instantlyNo watermark
- 1Choose toolOpen the Vootkit workspace.
- 2Add inputProvide the content or settings.
- 3ProcessLet the browser do the work.
Private by designProcessed on your device where possible.
Works on any deviceDesktop, tablet and mobile browsers.
No installationOpen the page and start working.
Always free coreUse the free plan for everyday tasks.
How to use Date Calculator
Provide the content or settings.
02Let the browser do the work.
03Copy, download or continue.
04Your files stay private
Your work is processed locally in your browser where possible and is never added to a Vootkit upload library.
Learn more about privacyDate arithmetic looks trivial and is not. Months have different lengths, years occasionally have an extra day, and the rules for what counts as a working day change the moment you cross a border.
What Date Calculator does
Finds the number of days between two dates, and adds or subtracts a period from a date to give the resulting one.
It counts calendar days rather than working days, which is the right basis for contracts and notice periods and the wrong one for project schedules.
Rules being applied
| Leap years | Divisible by 4, except centuries, unless divisible by 400 — 2000 was, 1900 was not |
|---|---|
| Days counted | Calendar days, including weekends and holidays |
| Inclusive or exclusive | The difference excludes the start date and includes the end |
| Month arithmetic | 31 January plus one month clamps to the end of February |
| Time zones | Not applied — dates are treated as plain calendar dates |
| Range | Any dates the browser can represent, well beyond any practical need |
Detailed steps
- Pick your two dates, or a start date and a period to add.
- Decide whether your deadline counts the start day. "Within 30 days" usually does not.
- Read the result in days, then convert to weeks or months if that reads better.
- For anything contractual, check whether the agreement means calendar or business days.
Worth knowing
The inclusive-versus-exclusive question causes more real disputes than leap years ever will. "Within 14 days of receipt" almost always means the day after receipt is day one, so an item received on the 1st is due on the 15th — but "14 days including today" makes it the 14th. On a notice period, a rent deadline or a returns window, that single day is the difference between being on time and being late, and it is worth reading the exact wording rather than assuming.
Frequently Asked Questions
Does the count include both the start and end dates?
The difference excludes the start date and includes the end one, which is the standard convention — from the 1st to the 8th is seven days. If your contract counts differently, and some do, add or subtract one accordingly. The wording to look for is "clear days", which usually means excluding both ends.
How are leap years handled?
Correctly, including the century rule that catches most manual calculations: a year divisible by 4 is a leap year unless it is divisible by 100, unless it is also divisible by 400. So 2000 had a 29 February and 1900 did not — a distinction that broke a great deal of software written in the 1990s.
What happens when I add a month to 31 January?
It clamps to the last day of February, so 28 or 29 depending on the year, because 31 February does not exist. This is the standard behaviour and it is worth knowing that it is not reversible: adding a month and subtracting one again does not always return you to the date you started from.
Can it count only working days?
No — it counts calendar days, which is what contracts, notice periods and statutory deadlines almost always mean. Working-day counts depend on which public holidays apply where you are, and a tool that guessed at that would be confidently wrong for most of the people using it.
Is Date Calculator free?
Yes. The Vootkit free plan includes 5 tool runs a day. Upgrade to Vootkit Pro for unlimited daily use, an ad-free workspace and saved workflows.
Are my files uploaded?
No. Date Calculator runs entirely in your browser — your file is processed on your own device and never sent to a server. There is nothing for us to store or delete.
Do I need to install anything?
No. Date Calculator works in any modern browser on desktop, tablet or phone. Open the page and start.
How often can I use it? Is there a daily limit?
On the free plan you get 5 tool runs a day. When you reach the limit you'll see a prompt to upgrade, and it resets the next day. Vootkit Pro removes the cap entirely for unlimited daily use.
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This tool processes everything locally in your browser. You can disconnect from the internet after the page loads and it will still work.