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Holiday API

Holiday API is a commercial reference-data service that delivers verified public holidays, observances, country and language metadata, and workday calculations for 250 countries and 3,680+ state/province subdivisions in 100+ languages. Operated by Gravity Boulevard, LLC, it exposes five JSON endpoints under https://holidayapi.com/v1/ with official client libraries for Go, Node.js, PHP, Python, Ruby, and Raku.

agent ready

Solid contracts, transparent operations, and an easy start — typically complete on four or five facets with one clear soft spot.

Kin Score

API Evangelist profiles Holiday API the way a machine reads it — 48 machine-readable artifacts across 4 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Holiday API scores 61.9/100 (strong), with a separate agent-readiness read of 45/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 61.9/100 · strong
Contract Quality 16.8 / 25
Developer Ergonomics 6.5 / 20
Commercial Clarity 14.7 / 20
Operational Transparency 3.4 / 13
Governance 10.4 / 12
Discoverability 10.0 / 10
Agent readiness — 45/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 7 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3

How we profile Holiday API

Each block below is one kind of artifact we hold for Holiday API. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 4

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

Individual APIs this provider publishes, each with its own machine-readable definition.

Holiday API Countries API

Country metadata, codes, languages, currencies, and subdivisions.

Holiday API Holidays API

Public holidays and observances for countries, states, and provinces.

Holiday API Languages API

Supported languages for retrieving localized holiday names.

Holiday API Workdays API

Working / business day calculations honoring country workweeks and holidays.

Pricing Plans 1

Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.

Published pricing tiers and plan structures.

Rate Limits 1

Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.

Documented rate limits and quota policies.

Holidays Rate Limits

1 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.

Cost, billing, and metering signals for API financial operations.

Features 9

The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.

Notable capabilities this provider offers.

Verified Holiday Data

Proprietary holiday generation system continuously verifies holidays for 250 countries.

Subdivision Coverage

3,680 state and province subdivisions on the States & Provinces plan via ISO 3166-2.

100+ Languages

Localized holiday names in over 100 languages via ISO 639-1 codes.

Workday Calculator

Get workdays and count business days between dates honoring country-specific workweeks and holidays.

Historic and Future Dates

Coverage from year 1 through year 2050+ on paid plans.

Multiple Response Formats

JSON, XML, YAML, CSV, TSV, and PHP serialization.

Offline Storage

Unlimited offline caching during active paid subscription; 24-hour window on free tier.

No Velocity Throttling

All plans share a monthly request quota (1M requests/month) with no per-second or per-minute limits.

Five-Nines Uptime

Enterprise-grade infrastructure designed for 99.999% availability.

Scroll within the panel for all 9 ·

Semantic Vocabularies 1

JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.

JSON-LD contexts and semantic vocabularies used across these APIs.

Holidays Context

16 classes · 17 properties

JSON-LD

Spectral Rules 2

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

Holiday API API Rules

5 rules · 4 warnings

SPECTRAL

Holiday API API Rules

16 rules · 9 errors · 7 warnings

SPECTRAL

JSON Schema 5

Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.

Standalone JSON Schema definitions for this provider's data models.

Country

8 properties

JSON SCHEMA

Holiday

8 properties

JSON SCHEMA

Language

2 properties

JSON SCHEMA

Response

4 properties

JSON SCHEMA

Workday

2 properties

JSON SCHEMA

JSON Structure 5

JSON Structure captures the data shapes in a form built for tooling — a complement to JSON Schema that keeps the model machine-legible.

JSON Structure definitions describing this provider's data shapes.

Holidays Country Structure

8 properties

JSON STRUCTURE

Holidays Holiday Structure

8 properties

JSON STRUCTURE

Holidays Language Structure

2 properties

JSON STRUCTURE

Holidays Response Structure

4 properties

JSON STRUCTURE

Holidays Workday Structure

2 properties

JSON STRUCTURE

Examples 6

Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.

Example request and response payloads for these APIs.

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Holidays Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.

Recommended x-agentic-access execution contracts for AI agents.

Holidays Agentic Access

5 operations

5 operations · 0 acting

AGENTIC

Use Cases 7

What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.

What developers build with this provider.

Calendar and Scheduling Apps

Mark public holidays on calendar UIs and prevent scheduling on non-business days.

Business Day SLA Calculation

Compute promised-by dates that honor weekends and country-specific holidays.

HR and Payroll Systems

Determine paid time off, observed holidays, and country-specific leave eligibility.

Localized Marketing Campaigns

Time outreach to align with public holidays in target countries and languages.

E-commerce Fulfillment

Forecast shipping ETAs that respect carrier and destination-country holidays.

Financial Settlement

Adjust transaction value dates and settlement windows around bank holidays.

Global Workforce Management

Coordinate distributed teams across regions with accurate observed-holiday data.

Scroll within the panel for all 7 ·

Integrations 4

Pre-built integrations with other platforms tell you where this provider already fits in a stack.

Pre-built integrations with other platforms and tools.

Spreadsheets

Pull holiday data into Google Sheets / Excel via the JSON, CSV, or TSV format options.

BI Tools

Feed holiday and workday data into Looker, Tableau, or Metabase for calendar dimensions.

Workflow Automation

Trigger Zapier or n8n flows on upcoming/previous holidays per country.

Calendar Platforms

Sync verified holiday data into Google Calendar, Outlook, or iCal feeds.

Resources

Every other property we hold for Holiday API — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Get Started 3

Portal, sign-up, and the first successful call

Documentation 3

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Build 8

SDKs, sample code, and the tooling you integrate with

Scroll within the panel for all 8 ·

Access & Security 1

Authentication, authorization, and security posture

Operate 2

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 1

The organization behind the API

Other 1

Properties that don't map to a standard resource type

← All providers · Data indexed from github.com/api-evangelist/holidays · machine-readable index on apis.io