Questions it answers
Count workdays, office days and PTO days between two dates, add business days for an SLA due date, or list bank holidays and school breaks. Ask "how many working days are there between 14 July and 18 August in Germany?", "what date is 37 business days after 11 August in England?", "is Monday a bank holiday in Bavaria?" or "what are the school holidays in Bavaria?".
Business Days and Workday Calculator does the date arithmetic exactly and reads each country's public holidays from Nager.Date, the UK's bank holidays from GOV.UK and school holidays from OpenHolidays, so the result does not depend on a guess about which days are holidays. People also call it OpenKrill Business Days. It does not count trading days, banking days, or settlement days.
It says how it counted. A working day is any day that is not a weekend day (Saturday and Sunday unless you set another weekend) and not a public holiday of the country or region. When you add days, the start date is day 0 and is not counted; when you count a range, both ends are counted unless you say otherwise. Bank holidays that are not days off, optional days and half days such as Christmas Eve count as working days.
Add a region (for example DE-BY, GB-SCT or US-CA) to include that region's holidays. Without one, holidays that only some regions keep are not counted, and the answer lists them so you can see the difference.
It covers more than 200 countries and territories for public holidays and a smaller set, mostly in Europe, for school holidays. It moves up to 1000 business days at a time and reads up to eight calendar years in one question. Company closures, local observances and legal deadline rules are not included, so check the official calendar and the contract before relying on a date.
It stores nothing about you: answers are cached for up to 24 hours, and the only lasting record is a daily count of calls per tool.
Short questions this server answers, each with a direct answer: Count working days and business-day due dates.
What it can do
- Counts workdays, office days and PTO days between two dates for a country or region
- Adds or subtracts business days from a date, skipping weekends and public holidays
- Lists bank holidays and statutory public holidays of a country and year, by region
- Lists school holidays and school breaks where they are published
- States how days were counted, including the weekend and which holidays were applied
Tools
count_business_days, Count working days, workdays and PTO. Use this when the user asks how many working days, business days, workdays, office days or PTO days there are between two dates, or for a statutory holiday count, for example "how many working days between 14 July and 18 August in Germany?", "how many working days are left in December in Ontario?" or "does 16 days of leave cover 5 to 31 December?". Pass the country code, the start and end dates as YYYY-MM-DD, and a region when the user names a state or province. Both dates are counted by default (includeStartDate and includeEndDate change that). Weekends are Saturday and Sunday unless weekendDays is set. Returns the number of business days, calendar days and weekend days, the public holidays that fell on working days, the holidays only some regions keep, and the conventions used. Do not use it for hours, time zones, or date differences that do not exclude weekends and holidays.add_business_days, Calculate a business-day due date and SLA. Use this when the user asks what date is a number of working days, business days or workdays after or before a date, including an SLA due date or turnaround, for example "what date is 37 business days after 11 August in England?", "when is payment due 30 business days from invoice date 3 March in Germany?" or "5 working days before 20 December in the US". Pass the country code, the start date as YYYY-MM-DD, the number of days (negative for earlier) and a region when the user names one. The start date is day 0 and is not counted. Returns the resulting date and weekday, the holidays skipped, and the conventions used. At most 1000 business days. Do not use it for legal deadlines that follow their own court or contract rules, or for calendar-day offsets.list_holidays, List bank holidays and school breaks. Use this when the user asks which public holidays, bank holidays, statutory holidays or school breaks a country, state or province has in a year, for example "is Monday a bank holiday in Bavaria?", "public holidays in Vietnam in 2027" or "school holidays in Bavaria". Pass the country code and the year, a region when the user names one, and kind school for school holidays, which are published for a limited set of countries. Public holidays come back with the date, weekday, English and local name, whether they apply nationwide or in listed regions, and whether they are a day off. Do not use it for religious or cultural festival dates without a country, trading-day calendars, or company holidays.
Add Business Days & Workday Calc in VS Code
VS Code reads MCP servers from mcp.json and offers their tools to Copilot Chat in Agent mode. A workspace file at .vscode/mcp.json applies to that project. For every workspace, run MCP: Open User Configuration from the Command Palette and add the same entry there. These steps were checked against the VS Code MCP servers guide on 2026-10-09.
Create or edit the file so it contains this server. VS Code uses a top-level servers object, not mcpServers. Merge it with servers you already have.
{
"servers": {
"business-days": {
"type": "http",
"url": "https://businessdays.openkrill.app/mcp"
}
}
}No command, no headers and no input variables for a key: Business Days & Workday Calc answers without a login. Save the file and select Start above the entry. VS Code asks once whether you trust the server: confirm it. Run MCP: List Servers to check that Business Days & Workday Calc is running. You should see count_business_days, add_business_days, list_holidays.
Open the Chat view, choose Agent mode and ask: How many working days are there between 14 July and 18 August 2026 in Germany? The Configure Tools button in the chat input lists the tools of each server, and VS Code may ask you to confirm the first call. The server is public and read-only. It sees only the arguments of each call, so do not paste secrets into the question.
Command line users can add it to the user profile in one step with code --add-mcp and the same name, type and url as JSON. The portable .mcp.json at the project root also works in VS Code, with mcpServers as its top-level key. An organization can turn MCP off through Copilot policy: if the MCP commands are missing, ask the admin.
If it does not work
The tool does not show up
Run MCP: List Servers, select the server and choose Restart. If it shows an error, choose Show Output to read the log. Check that the entry sits under servers with "type": "http", and that Chat is in Agent mode, where MCP tools are offered.
429 or rate_limited
Each server takes 60 calls a minute from one network, and some tools take fewer. Past that the call comes back as a tool error that starts with rate_limited: wait a minute and ask again. daily_limit means the server reached its shared daily cap, which resets at 00:00 UTC. A limit is not an answer, so do not read it as no results. For higher limits, ask support@openkrill.app for a key.
JSON entry has no type
Claude Code skips an entry in .mcp.json that has a url but no type. Add "type": "http" next to the url, or add the server with claude mcp add --transport http, which writes the type for you. The VS Code entry needs the same type field. Cursor and Pi read the url alone.
A call checked on 2026-10-17
Germany 2026 is a published Nager.Date calendar, so the holiday names can be checked. The request below was posted to https://businessdays.openkrill.app/mcp as tools/call. HTTP 200. Source: the Business Days & Workday Calc server, read 2026-10-17.
{
"method": "tools/call",
"params": {
"name": "list_holidays",
"arguments": {
"country": "DE",
"year": 2026
}
}
}
- source. Public holidays: Nager.Date (date.nager.at). School holidays: OpenHolidays (openholidaysapi.org).
- year. 2026
- country. DE
- publicHolidays. 19 returned
- publicHolidays name. New Year's Day
- publicHolidays date. 2026-01-01
Repeat the call yourself if you need a newer reading. Cached answers expire. A rate limit is not a result: wait and try again. Nothing in the call is a ranking, a filing, or advice.
Using it in production
Nothing to install and nothing to run: no package, no Python or Node.js version and no environment variable. Business Days & Workday Calc runs on our servers, and your client only needs the URL https://businessdays.openkrill.app/mcp.
| Rate limit | 60 tool calls a minute from one network. initialize and tools/list do not count. |
|---|---|
| Daily cap | 5000 tool calls a day per server, shared by every caller. It resets at 00:00 UTC. |
| At a limit | The call comes back as a tool error that starts with rate_limited (wait a minute) or daily_limit (try after 00:00 UTC), never as a partial answer. |
| Key | None. Do not add an Authorization header or a key field. |
| Higher limits | Email support@openkrill.app with the server name, the calls a day you expect and what they are for. We answer within 1 business day. |
| Freshness | Some answers come from a short cache. Each guide shows the date of its checked call; repeat a call when you need a newer reading. |
| Uptime | Scheduled test calls check the servers through the same endpoint. There is no SLA yet. |
| Data | What each server receives and keeps is on the privacy page. |
Use it in other apps
- Business Days & Workday Calc in ChatGPT
- Business Days & Workday Calc in Claude
- Business Days & Workday Calc in Cursor
- Business Days & Workday Calc in Pi
Roles that use Business Days & Workday Calc
Frequently asked questions
How do I install the Business Days & Workday Calc MCP server in VS Code?
Add business-days with type http and the url https://businessdays.openkrill.app/mcp under servers in .vscode/mcp.json and save the file. Select Start above the entry, confirm that you trust the server, then use it from Chat in Agent mode.
Do I need an API key to run Business Days & Workday Calc in VS Code?
No. This server takes no API key. For higher limits, email support@openkrill.app with the server name (Business Days & Workday Calc), the calls a day you expect and what they are for. We answer within 1 business day.
What should I do if Business Days & Workday Calc does not connect in VS Code?
Check that the entry sits under servers, not mcpServers, and has type http. Run MCP: List Servers, select business-days and choose Restart, then open Show Output if it still fails.