# Quiet Week Finder

> Find the weeks when the main visitor countries of a destination are not on holiday. Name the countries most visitors to a place come from, with weights, and get a crowd index for every week: how much of each country is on school or public holiday. The lowest weeks are the quiet ones for a trip, a booking or an errand.

Part of usefulweb.app (https://usefulweb.app/). Part of [Hearth](https://hearth.usefulweb.app/) (ownerApp: hearth). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://hearthquietweeks.usefulweb.app/ (interactive tool at https://hearthquietweeks.usefulweb.app/tool)
- JSON API: POST https://hearthquietweeks.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://hearthquietweeks.usefulweb.app/api/v1/tool)
- OpenAPI: https://hearthquietweeks.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://hearthquietweeks.usefulweb.app/mcp - tool `hearth_quiet_weeks`

## Inputs
- visitors (text, required): Visitor countries with weights - Two-letter codes, optional weights, for example “DE:3, NL:2, BE:1”. Include the destination’s own country for local visitors.
- from (date, required): Period from
- to (date, required): Period to

## Method
- Loads the school holidays and public holidays of every visitor country for the period from the OpenHolidays API (cached for a week).
- For each country and day, the holiday share is 1 for a nationwide holiday, otherwise the share of the country’s regions (top-level subdivisions that appear in its holiday data) that are off school or on a public holiday that day.
- The crowd index of a week (Monday–Sunday) is the weighted average of these daily shares over the seven days and the visitor countries: 0 = nobody is on holiday, 100 = every visitor country is fully on holiday all week.
- Quiet weeks are the five lowest; quiet stretches are runs of consecutive weeks at or below 10.

## Limits
- Regions are counted equally, not by population, and holidays only stand in for crowds: events, weather and local festivals matter too.