Give your AI assistant exact answers for dates people ask about all the time. It computes them from the official rules, with no API key and no sign-up.
Server URL (Streamable HTTP):
https://free-calendar-dates-mcp.simpletonfacts.workers.dev/mcp
church_calendar_dates — Ash Wednesday, Palm Sunday, Good Friday, Easter Sunday, Ascension, Pentecost, Trinity Sunday and the First Sunday of Advent for a year (Western), plus Orthodox Easter (Gregorian date).us_federal_holidays — All US federal holidays for a year with the actual date and the observed date (Saturday holidays observed Friday, Sunday holidays observed Monday).next_us_federal_holiday — The next US federal holiday (by observed date) on or after a given date, and how many days away it is.us_daylight_saving_time — When US daylight saving time starts (clocks spring forward) and ends (clocks fall back) in a year.us_estimated_tax_due_dates — The four IRS Form 1040-ES quarterly estimated tax due dates for a tax year, moved to the next business day for weekends and legal holidays. Standard rules only; the IRS can postpone deadlines for disasters.golden_hour — Sunrise, sunset, morning and evening golden hour and blue hour for any place and date, for photography planning.Claude: Settings → Connectors → Add custom connector → paste the URL above.
Claude Code:
claude mcp add --transport http free-calendar-dates https://free-calendar-dates-mcp.simpletonfacts.workers.dev/mcp
Cursor / other clients (mcp.json):
{ "mcpServers": { "free-calendar-dates": { "url": "https://free-calendar-dates-mcp.simpletonfacts.workers.dev/mcp" } } }
Same data as CSV, JSON and a static API: open datasets · JSON API · live badges.
Made by Honest Little Apps. Stateless, no logging of your questions, MIT licensed.