Add Days to Date Calculator
Add a chosen number of days, weeks or months to a starting date.
Calculator
Results
How it works
Add a chosen number of days, weeks or months to a starting date.
Example
| Example | Result |
|---|---|
| Mar 10, 2026 + 30 days | Apr 9, 2026. |
Important notes
- Calendar calculations use Gregorian calendar rules.
- Business-day calculations exclude Saturday and Sunday unless stated otherwise.
- Time-zone calculations depend on the browser's IANA time-zone data.
- For planning purposes, verify dates and times when a contractual or legal deadline is involved.
Frequently Asked Questions
Can I add months?
Yes. Month arithmetic is calendar-based and clamps invalid month-end dates.
Are weekends excluded?
No. Use the Business Days Calculator for weekday-only calculations.
How to use this calculator
What to enter
Enter or select the following as requested: Start date; Amount; Unit. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The date or duration result is calculated from the entered dates, times, calendar rules, and exclusions. Check inclusive versus exclusive counting, time zone, daylight-saving changes, and whether weekends or holidays are excluded.
When to use it
Use this to plan a date, measure elapsed time, or estimate a deadline. Verify the relevant calendar, location, and legal or workplace rules when they affect the answer.