Enter a starting date and the number of days to add. The resulting date, weekday and long date are shown automatically.
Add Days to a Date
1. Starting date:
2. How many days should be added?
Answer:
How the calculator works
The tool adds an integer number of calendar days to the selected date. Negative numbers find an earlier date. Month lengths and leap years are handled automatically.
Practical examples
| Starting date | Days to add | Resulting date |
|---|---|---|
| 2026-01-01 | 30 | 2026-01-31 |
| 2026-02-15 | 90 | 2026-05-16 |
| 2026-03-01 | 365 | 2027-03-01 |
| 2026-06-10 | 7 | 2026-06-17 |
Frequently asked questions
How does the add-days calculator work?
Choose a starting date and enter the number of calendar days to add. The result includes the date and weekday.
Can I add a negative number of days?
Yes. A negative number subtracts days and returns an earlier date.
Does it account for leap years?
Yes. Leap years and the correct number of days in each month are handled automatically.
Can I enter decimal days?
No. The number of days must be an integer.
See also…
