Date add and subtract calculator
Add or subtract days, weeks, months and years from any date. Optionally count only business days excluding weekends.
- Free, no sign-up
- No data stored
- Reviewed 2026-01-15
Your details
Results
Result date
Monday, 21 September 2026
22 Aug 2026 + Every :interval
- Weekday
- Monday
- Iso date
- 2026-09-21
- Day of year
- 264
- Week number
- W39 · 2026
- Days shifted
- 30
- Unix timestamp
- 1789948800
Offsets table
| Days | Forward | Backward |
|---|---|---|
| 1 | 23 Aug 2026 (Sun) | 21 Aug 2026 (Fri) |
| 7 | 29 Aug 2026 (Sat) | 15 Aug 2026 (Sat) |
| 14 | 5 Sep 2026 (Sat) | 8 Aug 2026 (Sat) |
| 30 | 21 Sep 2026 (Mon) | 23 Jul 2026 (Thu) |
| 60 | 21 Oct 2026 (Wed) | 23 Jun 2026 (Tue) |
| 90 | 20 Nov 2026 (Fri) | 24 May 2026 (Sun) |
| 180 | 18 Feb 2027 (Thu) | 23 Feb 2026 (Mon) |
| 365 | 22 Aug 2027 (Sun) | 22 Aug 2025 (Fri) |
Formats table
| Format | Value |
|---|---|
| ISO 8601 | 2026-09-21 |
| RFC 2822 | Mon, 21 Sep 2026 00:00:00 +0000 |
| Long date | Monday, 21 September 2026 |
| Short date | 21/09/2026 |
| Unix | 1789948800 |
About the Date Add/Subtract Calculator
Start with any date and add or subtract a combination of years, months, weeks and days. A "business days only" option skips weekends, useful for deadline and delivery-date calculations.
How to use the Date Add/Subtract Calculator
- Enter the starting date.
- Choose add or subtract.
- Enter the amounts (years, months, weeks, days).
- Optionally tick business days only.
- View the resulting date.
Frequently asked questions
How does adding months work across month boundaries?
If the resulting day exceeds the target month (e.g. 31 Jan + 1 month), it rolls to the last day of the target month (28/29 Feb).
Does business days skip public holidays?
Currently it skips Saturdays and Sundays only. Public holidays vary by country and are not automatically excluded.
Can I combine years, months and days?
Yes. They are applied in order: years first, then months, then weeks and days.