festivos.io is open on purpose. You may copy, redistribute, adapt and use the data even commercially — all we ask for is attribution.
The data files (JSON and ICS under /v1/) are published under Creative Commons Attribution 4.0 International. The license also covers the EU sui generis database rights: you may extract and reuse substantial parts as long as you cite the source.
How to attribute — include this text and link visibly:
Data from festivos.io — CC BY 4.0 — https://festivos.ioEach file already includes the license, attribution, last_updated and official source fields for every record, so citing is trivial and verifiable.
The ingestion pipeline and tooling are published under the MIT license.
Every query endpoint is free and requires no API key, including batch and working-day operations. The service keeps reasonable per-IP limits to prevent abuse; those limits do not separate plans or restrict the data licence.
Holidays and deadlines may be corrected during the year. festivos.io does not replace the official sources (BOE, regional gazettes, municipal decrees, AEAT): always check the source —linked on each record— before making legal, employment or tax decisions. Service provided "as is", without warranty.