Calendar infrastructure for product workflows
About Calendar Intelligence
Calendar Intelligence helps product teams, internal tools, and AI agents answer date questions without hardcoding business day, trading day, market hours, timezone, or public holiday rules in each application.
It turns messy date logic into clear product answers: when a week starts, whether a market is open, how many business days sit between two dates, and which timezone a timestamp actually belongs to.
GET /v1/markets/schedule
market=XNYS&date=2026-07-03
GET /v1/business-days/diff
country=US&start_date=2026-06-29&end_date=2026-07-06
https://calendar-api.plus1labs.com
Seeded data window
2020-01-01
2030-12-31
Supported countries
10
AU, CA, CN, DE, FR, GB, HK, JP, SG, US
Supported markets
7
XHKG, XLON, XNAS, XNYS, XSHE, XSHG, XTKS
Why it exists
Most time tools stop at timestamp conversion. Real products need more context: public holidays, exchange closures, early closes, settlement calendars, and localized business-day rules. Calendar Intelligence brings those decisions into one consistent API and a friendlier tool workspace.
Product teams building scheduling, billing, trading, compliance, and operations workflows.
Developers who need a quick, explainable answer before wiring calendar logic into code.
AI agents and MCP clients that need deterministic date tools instead of vague reasoning.
What it understands
Calendar boundaries for weeks, months, quarters, and years.
Country public holidays, next-holiday lookup, and holiday checks.
Business-day checks, offsets, and differences across supported countries.
Exchange trading days, market schedules, next trading days, early closes, and settlement dates.
IANA timezone listing and timezone conversion for global planning.
Product principles
Human-readable results first, raw JSON when developers need it.
Clear distinction between calendar days, business days, and trading days.
Configurable links, analytics, ads, and contact channels with no hardcoded production IDs.
REST and MCP surfaces so both web users and AI clients can use the same calendar logic.
Coverage
The current seeded data window is intentionally explicit so teams can reason about valid inputs and avoid silent assumptions.
Seeded country and market calendars cover 2020-01-01 to 2030-12-31.
Supported countries
Supported markets
Developer surfaces
Use the product tools for everyday lookup, the API workbench for endpoint-level debugging, or the MCP endpoint for agent workflows.