Add or subtract days from a date
Enter a start date and add or subtract days, weeks, months, years or business days to find the resulting date and its weekday. It runs in your browser (0 uploads, works offline).
How to use it
- Enter the dates or values in the fields above.
- The result and a plain-language explanation appear instantly.
- Copy or Download the result.
FAQ
How do I add days to a date online for free?
Enter the start date, a number, and a unit — the resulting date appears instantly in your browser with no upload. Use a negative number to go backwards, and pick "business days" to skip weekends.
How does adding months work at the end of a month?
Adding a month clamps to the end of a shorter month, so 31 January plus one month is 28 February (or 29 in a leap year) rather than rolling into March. This matches how deadlines are normally counted.
Is my data uploaded?
No. The calculation runs locally and nothing is stored; it works offline.
What are business days here?
Days excluding Saturday and Sunday. Public holidays are not assumed — for those, use the business-days calculator.
Limits
Business-day mode skips weekends only. Month/year addition clamps to the target month end.
Related
The business-days calculator counts working days in a range; the notice-period calculator finds a last working day.
Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.