Add or Subtract Days from Date
Add to or Subtract Days/Weeks/Months or Years from a Date
"Add or Subtract Days from Date" Calculator
How the date is counted
Worked example: 90 days from Monday, Sep 21, 2026
Sep 21Dec 20
The start date is day 0. 90 days from September 21: September 21 is day 0, December 20 is day 90.
→ Sunday, Dec 20, 2026 · open this calculation
- Calendar days. Weekends and holidays count like any other day; a week is 7 days, so 12 weeks = 84 days.
- Months and years keep the day number; when the target month is shorter, the date is its last day: August 31 + 6 months = February 28, 2027.
- The year. A page like “90 days from September 21” counts from this year’s date, 2026. For another year, pick the full date in the form above.
| Calculation | Date |
|---|---|
| 90 days from Nov 3 | Mon, Feb 1, 2027 |
| 30 days from Nov 3 | Thu, Dec 3, 2026 |
| 60 days from Nov 3 | Sat, Jan 2, 2027 |
| 6 months from Nov 3 | Mon, May 3, 2027 |
| 45 days from Nov 3 | Fri, Dec 18, 2026 |
| 28 days from Nov 3 | Tue, Dec 1, 2026 |
| 180 days from Nov 3 | Sun, May 2, 2027 |
| 12 weeks from Nov 3 | Tue, Jan 26, 2027 |
See Also
- Date Calculator - Add to or Subtract Days/Weeks/Months or Years from Today
- Weeks and Days Ago From Today - Calculate what day was it Weeks and Days Ago From Today
- Days Between Two Dates - Calculate the Difference Between Two Dates. How many days, months, and years are between two dates? From date to date calculator
- Days until Date - How many days, weeks, months and years until a Date. How Many Days Until My Birthday? Countdown to date
FAQ
How do I add or subtract days from a date?
Enter the number, choose days, weeks, months or years and 'From' or 'Before', pick the start date in the date field, then press Calculate. The start date is day 0.
Can I subtract weeks, months, or years instead of days?
Yes — the Period field lets you switch between days, weeks, months, and years, so you can add or subtract any of these units from the same starting date.
Does the calculator account for leap years?
Yes. Day-based calculations count actual calendar days, so leap years (like February 29) are automatically included in the result.