Quartermaster

Tools / Developer utilities

Public Holiday Check $0.001 / call

Is a date a public holiday in a country?

GET /v1/holiday

Tells you whether a date is a public holiday in a given country (2-letter ISO code), the holiday's name, and the next upcoming holiday that year. For scheduling agents deciding when work will or won't happen. Data from the free Nager.Date service.

Parameters

country required2-letter ISO country code, e.g. US, GB, DE
dateYYYY-MM-DD (defaults to today, UTC)

Example

macOS / Linux 
curl -s "https://quartermaster.surewhynot.app/v1/holiday?country=US&date=2026-01-01"
Windows (cmd or PowerShell) 
curl.exe -s "https://quartermaster.surewhynot.app/v1/holiday?country=US&date=2026-01-01"

Unpaid, these return 402 Payment Required with the payment details in the header (add -i to see them). curl.exe ships with Windows 10+ and works in cmd and both PowerShell versions. To actually pay, use an x402 client (see Connect) or call it as the MCP tool. Cost: $0.001 per call.

FAQ

Which countries are supported?
The ~110 countries covered by the Nager.Date public-holiday dataset, addressed by ISO 3166 two-letter code. Unknown codes return a clear error.
What about holidays that fall on a weekend?
Dates are the observed public holiday — when businesses are actually closed. If a holiday shifts (e.g. July 4 on a Saturday is observed the Friday before), that observed date is what returns true, which is what scheduling actually cares about.
How do I pay for this endpoint?
Call it with no payment and you receive HTTP 402 with machine-readable payment requirements. Attach a USDC payment on Base with any x402 client (for example @x402/fetch) and retry — the whole loop is two requests. This call costs $0.001 in USDC.
Do I need an account or API key?
No. There are no accounts, logins, or API keys anywhere in Quartermaster. Payment is per call over the x402 protocol; your wallet is your identity.
Can I call this as an MCP tool instead?
Yes. Quartermaster is also an MCP server at /mcp, so any MCP client (Claude Code, Claude.ai, Cursor) can mount this tool. See /connect for setup.

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