Date Calculator

Date Calculator gives Claude exact date arithmetic instead of estimates. It counts the days between two dates, adds or subtracts days, weeks, months or years, and calculates business-day deadlines that skip weekends and official public holidays for a chosen country or region. It can also list a country's public holidays for any year and show which countries and regions are supported.

It uses the same calculator as onlinealarmkur.com. Every result includes the rules that were applied and a link that opens the same calculation on the website, so users can check it themselves.

All four tools are read-only and the server needs no account or authentication.

Limitations: it works with Gregorian calendar dates only, not times of day or time zones. Holiday data covers official public holidays and does not mark half-day holidays, so critical legal or tax deadlines should still be confirmed with the relevant authority.