# Business Days & Workday Calc

Count working days and public holidays for a country or region. It is free, with no sign-up and no key.

Also known as: OpenKrill Business Days, Business Days and Holidays, Workday Calculator, Bank Holiday Calendar.

## What it does

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.

- 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

## Who it is for

Anyone who asks an AI assistant a question like this one: “What date is 37 business days after 11 August in England?”

Roles that use it at work: Operations coordinator, Payroll or HR ops.

Role guides that use it: [Operations coordinator](https://tools.openkrill.app/for/operations-coordinator).

## Price

Business Days & Workday Calc is free to use. There is no sign-up, no account and no API key. Calls are limited to 60 calls a minute per network and 5000 calls a day per server, shared by all callers. Repeat questions are answered from a cache.

## Tools it offers

- `count_business_days`: Count working days, workdays and PTO
- `add_business_days`: Calculate a business-day due date and SLA
- `list_holidays`: List bank holidays and school breaks

## Connect

The MCP server is `https://businessdays.openkrill.app/mcp` (streamable HTTP). It needs no key.

Claude Code, in one command:

```
claude mcp add --transport http business-days https://businessdays.openkrill.app/mcp
```

Hermes Agent, in one command that answers its two setup questions (no key, enable all tools):

```
printf 'n\ny\n' | hermes mcp add business-days --url https://businessdays.openkrill.app/mcp
```

Or add these lines to `~/.hermes/config.yaml`, under an existing `mcp_servers:` key if the file has one. Start a new Hermes session after either step.

```
mcp_servers:
  business-days:
    url: https://businessdays.openkrill.app/mcp
```

Any other agent: give it this page's Markdown address, `https://tools.openkrill.app/tools/business-days.md`, and ask it to connect Business Days & Workday Calc.

Install guides, each checked with a real call: [Business Days & Workday Calc in ChatGPT](https://tools.openkrill.app/integrations/business-days/chatgpt), [Business Days & Workday Calc in Claude](https://tools.openkrill.app/integrations/business-days/claude), [Business Days & Workday Calc in Cursor](https://tools.openkrill.app/integrations/business-days/cursor), [Business Days & Workday Calc in VS Code](https://tools.openkrill.app/integrations/business-days/vscode), [Business Days & Workday Calc in Pi](https://tools.openkrill.app/integrations/business-days/pi).

## Job recipes for agents

Step-by-step recipes that walk an agent through 3 jobs with this server's tools:

- Count working days, workdays and PTO, with `count_business_days`
- Calculate a business-day due date and SLA, with `add_business_days`
- List bank holidays and school breaks, with `list_holidays`

[Download the recipes as SKILL.md](https://tools.openkrill.app/skills/business-days-jobs/SKILL.md). Save it as `business-days-jobs/SKILL.md` in your agent's skills folder. A connected MCP client gets the same recipes from `prompts/list` on the gateway, `https://api.openkrill.app/gateway/mcp`.

It is listed under Everyday checks in the [full tool list](https://tools.openkrill.app/tools). The same facts in plain text are in [llms.txt](https://tools.openkrill.app/llms.txt).

Source: the Business Days & Workday Calc listing, version 1.0.1. As of 2026-10-18.