A data product at the edge
The Worker handles authenticated API requests and tier-based daily limits. D1 stores the structured calendar and usage data; clients consume a stable JSON interface instead of maintaining separate gazette parsers.
DEVELOPER INFRASTRUCTURE / DATA API
Local calendars. One software interface.
Spanish national, regional and municipal holiday data through a JSON API, built for payroll, scheduling and applications that need to understand local working days.
FestivosAPI
ReleasedDSL4-owned developer API. Consult the live coverage endpoint for current calendar coverage and data states.
THE PRODUCT
What it solves.
A national calendar cannot answer whether a particular town observes a local holiday. FestivosAPI reconciles official calendars and municipal identifiers into a consistent interface that other software can consume.
THE ENGINEERING
How it works.
Cloudflare Workers serve the API, with D1 holding calendar data, municipal records and API usage counters. Scheduled refreshes collect source data. Exact municipal-name matching resolves official records to INE identifiers, while explicit coverage states distinguish available data, verified absence of a separate local holiday and unresolved coverage.
CLOUDFLARE & PRODUCT ARCHITECTURE
Inside the system.
Precision before apparent completeness
Name reconciliation uses exact matching. Ambiguous or unresolved municipalities are reported rather than guessed, and coverage is exposed separately from the holiday response.
Built to be maintained
Quarterly and annual refresh scheduling supports calendar updates. Source provenance and coverage reports make refresh gaps visible, which matters as consuming applications depend on successive calendar years.