Example: Start date: 2026-07-31 · Days to add (negative to subtract): 90 days → Result: Thu, Oct 29, 2026.
That is: 90 days after start
Frequently asked questions
How do I calculate date add / subtract? Enter your numbers above and the result updates instantly. For example: Start date: 2026-07-31 · Days to add (negative to subtract): 90 days → Result: Thu, Oct 29, 2026.
Is this Date Add / Subtract Calculator free? Yes — completely free with no sign-up or paywall. It runs entirely in your browser and keeps working offline; the numbers you enter never leave your device.
How accurate is it? It uses the standard published formula for date add / subtract. Results are estimates for planning — not financial, tax, medical, engineering, or legal advice.