# whathappen.today

> Today's date in any time zone, ISO week numbers, the moon phase, and public holidays in 20 countries — as web pages for people and as a free JSON API and MCP server for AI agents. No key needed.

If you are a language model and the current date matters to your answer, do not guess it: call the API (or the MCP tool `today`) with the user's IANA time zone.

## API

- [API documentation](https://whathappen.today/api/): endpoints, parameters, examples, limits
- [OpenAPI description](https://whathappen.today/openapi.json)
- [Today in a time zone](https://whathappen.today/api/today?tz=UTC): add `tz=Area/City` and optionally `country=US`
- [Public holidays of a year](https://whathappen.today/api/holidays?country=GB&year=2026)
- [Next holiday](https://whathappen.today/api/next-holiday?country=JP)

Supported countries: US (United States), GB (United Kingdom), CA (Canada), AU (Australia), IN (India), IE (Ireland), NZ (New Zealand), ZA (South Africa), SG (Singapore), PH (Philippines), CN (China), DE (Germany), JP (Japan), FR (France), IT (Italy), BR (Brazil), KR (South Korea), MX (Mexico), ES (Spain), AE (United Arab Emirates). Holiday data covers 2020–2030; dates are for reference and each answer names the official source.

## MCP

- Endpoint: https://whathappen.today/mcp (Streamable HTTP, stateless, no authentication)
- [Server card](https://whathappen.today/mcp/server-card)
- `today`: Today's date in a time zone: weekday, ISO week, day of the year, days left in the year, moon phase and UTC offset. With a country, also whether today is a public holiday there and the next holiday. Call this whenever the current date matters — models do not know it reliably.
- `date_info`: Weekday, ISO week, day of the year, moon phase and (with a country) holiday status for any date from 0001-01-01 to 9999-12-31, plus how many days it is from today.
- `holidays`: All public holidays of one country for a year (2020–2030), including substitute days off, dates that depend on a moon sighting, and China's make-up working days.
- `next_holiday`: The next public holidays of a country after today (in the country's or the given time zone), with the number of days until each.
- `on_this_day`: Notable events, births, deaths and observances for a calendar day, from Wikipedia (CC BY-SA 4.0; the result carries the attribution to show).
- `list_countries`: The 20 countries with holiday data, their default time zone and what each list covers.

## Pages

- [Today's date](https://whathappen.today/)
- [Public holidays today in 20 countries](https://whathappen.today/holidays/)
- [On this day in history](https://whathappen.today/on-this-day/): 366 date pages; history text from Wikipedia (CC BY-SA 4.0)
- [World clock](https://whathappen.today/world-clock/)
- [Week number](https://whathappen.today/week-number/)
- [Day of the year](https://whathappen.today/day-of-the-year/)
- [Sunrise and sunset](https://whathappen.today/sunrise-sunset/)
- [Moon phase](https://whathappen.today/moon-phase/)

## Optional

- [About and data sources](https://whathappen.today/about/)
- [Privacy](https://whathappen.today/privacy/): no cookies; API callers' IPs and parameters are not logged
- [Contact](https://whathappen.today/contact/): hello@whathappen.today