Tasks these servers can do
How many working days are there between 14 July and 18 August 2026 in Germany?
Call count_business_days on Business Days & Workday Calc (https://businessdays.openkrill.app/mcp). A count, the weekend rule, and the holidays that fell in the range. It does not know your company's extra closure days.
Install steps: ChatGPT, Claude, Cursor, VS Code, Pi.
What date is 37 business days after 11 August 2026 in England?
Call add_business_days on Business Days & Workday Calc (https://businessdays.openkrill.app/mcp). The resulting date, with the holidays that were skipped. It is not a legal deadline calculator.
Install steps: ChatGPT, Claude, Cursor, VS Code, Pi.
What are the public holidays in Bavaria in 2027?
Call list_holidays on Business Days & Workday Calc (https://businessdays.openkrill.app/mcp). Public holidays, and school holidays when you ask for that kind, from the published calendars.
Install steps: ChatGPT, Claude, Cursor, VS Code, Pi.
What they will not do
A contract that uses a different weekend, or a local observance the calendar does not list, will not match. Say the country and, when it matters, the region. Document Tools can turn a resulting date into an .ics file if you need a calendar invite.
Where to start
Each link above is a client-specific install page with one call that was checked against the live server. The plain-text list of every server is llms.txt specification. The words MCP, tool and streamable HTTP are defined in the MCP and agent glossary.