Business-day math
for AI agents

LLMs are bad at date math. JDay handles weekends, holidays, and regional calendars across 20 countries so your agents don't have to.

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One request. One answer.

Structured JSON designed for tool calling.

Request

GET /v1/is-business-day
  ?date=2026-04-03
  &country=ZA
Host: jday-api.jday.workers.dev
Authorization: Bearer jday_live_xxx

Response

{
  "date": "2026-04-03",
  "country": "ZA",
  "is_business_day": false,
  "reason": "public_holiday",
  "holidays": [{
    "name": "Good Friday",
    "type": "public"
  }],
  "next_business_day": "2026-04-07",
  "previous_business_day": "2026-04-02"
}

Built for agents. Correct by default.

Agent-First Design

Structured JSON responses built for tool calling. No HTML scraping, no ambiguous formats.

20 Countries at Launch

Australia, Canada, Germany, Japan, United Kingdom, United States, and 14 more.

MCP Server

Drop-in Model Context Protocol server. Works with Claude, ChatGPT, and any MCP-compatible agent.

Deterministic

Same input, same output. Every time. Counting rules, validation, and error behavior are part of the contract.

Regional Holidays

State and province-level holidays for AU, CA, DE, GB, and US. Over 100 regions supported.

Fast & Simple

5 endpoints. Bearer auth. JSON in, JSON out. p95 latency under 50ms.

20 countries at launch

Regional holiday support for 5 countries. Expanding after v1.

🇦🇺AustraliaRegional
🇦🇹Austria
🇨🇦CanadaRegional
🇩🇰Denmark
🇫🇮Finland
🇫🇷France
🇩🇪GermanyRegional
🇮🇪Ireland
🇮🇹Italy
🇯🇵Japan
🇳🇱Netherlands
🇳🇿New Zealand
🇳🇴Norway
🇸🇬Singapore
🇿🇦South Africa
🇰🇷South Korea
🇪🇸Spain
🇸🇪Sweden
🇬🇧United KingdomRegional
🇺🇸United StatesRegional

Simple, predictable pricing

Monthly quota is account-level. Per-second rate limits are key-level.

Free

$0

Get started with the core API.

  • -1,000 requests/month
  • -1 active API key
  • -All 20 countries
  • -5 core endpoints
  • -2 req/s rate limit
Start Free

Starter

$9/mo

Add regional holidays.

  • -25,000 requests/month
  • -50 active API keys
  • -Regional queries
  • -20 req/s rate limit
Coming Soon

Pro

$29/mo

For production workloads.

  • -200,000 requests/month
  • -50 active API keys
  • -Regional queries
  • -Priority support
  • -50 req/s rate limit
Coming Soon

Enterprise

Custom

For high-volume and custom needs.

  • -Custom quota
  • -50+ API keys
  • -Regional queries
  • -SLA guarantee
  • -Custom rate limits
  • -Priority support
Contact Us

Ready to get started?

Read the docs, grab an API key, and add reliable business-day logic to your agents in minutes.

Read the DocsAPI Reference