Date Calculator
Count calendar or working days and add or subtract days, weeks, months and years.
Hover over or focus a field for help. Press Escape to close.
How it works
Choose your options and run the tool. Copy the result or download it as a file.
A practical example
Dates
2026-01-01 → 2026-01-08
Result
7
Frequently asked questions
Is my input sent to a server?
No. Your content is processed in this browser. It is never sent to the server or saved.
What should I know about Date Calculator?
Choose the interval endpoints to include. For working days, select weekly days off and enter additional holidays as YYYY-MM-DD separated by commas. No national holidays are added automatically. End dates must be on or after start dates. Month and year operations clamp to the last valid day. Dates range from 0001 to 9999.