Date Add / Subtract
Add or subtract days, weeks, or months from a date.
Use on any page (bookmarklet)
Want Date Add / Subtract without leaving the page you're on? Drag the button below to your bookmarks bar, then click it on any website to open Date Add / Subtract right there — it runs entirely in your browser.
Use responsibly: a bookmarklet runs on whatever page you click it on. Avoid sensitive sites such as online banking, payment, or healthcare pages — you run it at your own risk. Everything is processed locally and no data is sent anywhere. See our Terms.
- Show your bookmarks bar if it's hidden — Ctrl+Shift+B (⌘+Shift+B on Mac).
- Drag the button above onto the bookmarks bar.
- Open any website and click the bookmark — the Date Add / Subtract panel appears in the top-right corner. Use ✛ to move it between corners, or ›/‹ to tuck it against the edge and pull it back out.
- Click the bookmark again (or the ✕) to close it.
Note: a few sites with strict security policies may block bookmarklets.
Examples
Add 30 days
Input
2025-01-01 + 30 days
Output
2025-01-31 (Friday)
Subtract 3 months
Input
2025-06-15 − 3 months
Output
2025-03-15 (Saturday)
About this tool
This free online date calculator adds or subtracts days, weeks, months, or years from any date. Pick a start date, choose add or subtract, enter an amount and unit, and the new date appears instantly with its day of the week. Everything runs in your browser with no upload.
How to use
- Choose a start date.
- Pick Add or Subtract and enter an amount.
- Choose the unit — days, weeks, months, or years.
Common uses
Finding a deadline a set number of days out, working out renewal or expiry dates, scheduling follow-ups, and counting back to a start date from a due date.
Frequently asked questions
How do I add days to a date?
Pick a start date, choose Add, enter the number of days, and the result date appears instantly — along with the day of the week it lands on.
Is this date calculator free?
Yes — it's a completely free online add/subtract date calculator with no sign-up.
Can I subtract weeks, months, or years?
Yes. Choose Subtract and pick the unit — days, weeks, months, or years — to count backwards from your start date.
How are months handled at the end of a month?
Adding months follows standard calendar behavior, so edge cases like January 31 plus one month roll into early March, matching how date libraries and spreadsheets behave.
Does it tell me the weekday of the result?
Yes. The result shows the new date and the day of the week, which is handy for scheduling.
Is my data uploaded anywhere?
No. The calculation runs entirely in your browser with no upload.
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