Date Calculator
Add or subtract calendar years, months, weeks, and days.
Your result will appear here
Enter your values and choose Calculate. Nothing is uploaded.
Method and formula
Adds or subtracts calendar years and months before weeks and days. End-of-month dates are clamped to the last valid day.
Example and limitations
Adding one month to 31 January lands on the last valid day of February.
Privacy by design. This tool processes your work locally in this browser session.
Made for a focused workflow
Date Calculator works locally in this browser session, with no account required.
What to expect
- Clear progress and recoverable errors
- Explicit file handling and privacy information
- No fabricated results while an engine is unavailable
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Frequently asked questions
How does Date Calculator work?
This tool runs in your browser. Follow the workspace prompts to complete the task.
Do I need an account?
No account is required for the basic browser tools currently available.
What happens to my files?
Files used by this tool stay in your browser for the current session.