US Business Calendar

US federal holidays, business-day maths, invoice due dates and IRS deadlines — for bookkeeping, payroll and AI agents.

For bookkeepers, payroll, AP/AR teams, small businesses and agent builders. Free: next federal holidays. Pro: business-day maths, due dates and IRS deadline calendars.

Free tier: next_holidays, no sign-up. Pro: $9/month — all tools, unlimited use. Cancel anytime (one click on the success page, or email).

Subscribe — $9/month

Tools

next_holidays (free) — FREE. Next 3 US federal holidays (with observed dates) and whether today is a business day.
business_days (Pro) — PRO. Count US business days between two dates (excludes weekends and federal holidays).
due_date (Pro) — PRO. Due date after N business days or N calendar days (rolled to next business day) — Net 30/60, ACH settlement, contract notice periods.
irs_deadlines (Pro) — PRO. Upcoming IRS filing and payment deadlines for the next N months (individual, payroll, corporate), adjusted for weekends/holidays; optional fiscal_year_end.

Live free example

next_holidays {}

{
  "today": "2026-10-14",
  "business_day": true,
  "next_3": [
    {
      "name": "Veterans Day",
      "date": "2026-11-11",
      "observed": "2026-11-11"
    },
    {
      "name": "Thanksgiving Day",
      "date": "2026-11-26",
      "observed": "2026-11-26"
    },
    {
      "name": "Christmas Day",
      "date": "2026-12-25",
      "observed": "2026-12-25"
    }
  ],
  "pro": "Business-day maths, invoice due dates, IRS deadlines, payroll planners: https://us-business-calendar-mcp.donniertf.workers.dev/buy",
  "disclaimer": "US federal holidays (OPM rules, observed dates) and standard IRS due dates rolled to the next business day. State holidays, disaster extensions and your own elections may change dates — check IRS.gov. Not tax advice."
}

Connect (MCP)

Add https://us-business-calendar-mcp.donniertf.workers.dev/mcp to Claude, Cursor or any MCP client (Streamable HTTP, no login for the free tier). Subscribers pass access_token or Authorization: Bearer.

Important

US federal holidays (OPM rules, observed dates) and standard IRS due dates rolled to the next business day. State holidays, disaster extensions and your own elections may change dates — check IRS.gov. Not tax advice.

Data sources & licences

OPM federal holiday rules (5 U.S.C. 6103)
IRS published due dates (rules encoded)

For AI agents

llms.txt · server card · pricing.json · POST /checkout → checkout URL · GET /token?session_id= → access token.

More US data MCPs

Save with US bundles: us-mcp-bundles · GitHub hub.

Contact & cancelling

Questions, refunds or cancelling: dmorrisonwebdesign@gmail.com. Run by Donnie Morrison, UK. Payments by Stripe; we never see card details.