Date Calculator
Add or subtract a number of days from a date to find the resulting calendar date and day of the week.
- Free to use
- Accurate results
- No registration required
- Works on all devices
Enter a start date, a number of days, and whether to add or subtract to find the resulting calendar date.
Your result
2026-10-12
Result date
Day of the weekMonday
AI explanation
Formula
Result date = start date ± number of daysWorked example
30 days after 2026-09-12
| Field | Value |
|---|---|
| Start date | 12-09-2026 |
| Number of days | 30 |
| Operation | add |
| Result date | 2026-10-12 |
| Day of the week | Monday |
Assumptions
- Dates are treated as calendar dates with no time-of-day or timezone component.
Frequently asked questions
Does this account for leap years automatically?
Yes — the underlying date arithmetic is fully calendar-aware, correctly handling February 29 in leap years.
Can I use this to find a date far in the past or future?
Yes — enter any whole number of days along with "Subtract days" or "Add days" to move that many days from the start date in either direction.
Is there a simpler version for just adding or subtracting days?
Yes — see the Add Days to Date Calculator and Subtract Days from Date Calculator for a single-purpose version of each direction.