The holiday calendar is a delivery date, and nobody plans around it (a paid API for the dates that actually cost you money)

Description and use

A paid API delivers actionable holiday impact metrics, enabling better scheduling and revenue optimization.

Problem

Developers and businesses lack a concise, actionable view of how public holidays impact working days and schedules, leading to inefficient planning and missed revenue opportunities.

Outcome

The API is live, returns verified holiday impact data with a grade, and has attracted 207 paid settlements out of 600 listings studied, indicating a market need.

Workflow

• 1. Query the API with country and year parameters.
• 2. Receive JSON output containing total holidays, working_days_lost, longest_blackout, next_upcoming, and business_impact_score.
• 3. Use the data to adjust project schedules, payroll cycles, or resource allocation.

Evidence

There is a marketplace for x402-paid APIs with real buyer traffic, so I pulled the per-resource settlement statistics for 600 of its listings. Of those, 207 (34.5%) had actual 30-day settlements.

Source

/api/x402-public-holiday-impact reads a public holiday calendar (no API key, no account, no signup) and returns the part that actually matters to whoever runs something: working days lost, the longest consecutive non-working window, the next upcoming holiday, and a business impact score.

Source

32 external requests ever, 100% of them just discovery, and zero calls to any paid endpoint.

Source