How to use the add or subtract days
- Choose the starting date.
- Select Add days or Subtract days and enter a whole number from 0 to 365000.
- Calculate to see the resulting calendar date.
Worked example
Adding 30 days to 1 November 2026 gives Tuesday, 1 December 2026. Adding zero days leaves the starting date unchanged.
Frequently asked questions
Are weekends skipped?
No. The tool adds or subtracts calendar days, including Saturdays, Sundays and public holidays.
Can I enter a negative number?
Use a positive number and choose Subtract days to move backwards.
Can I use this for a deadline?
It can help calculate calendar dates, but check whether your deadline uses working days, includes the starting day, or has holiday-specific rules.
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Updated 8 November 2026 · Built-in tools, no signup