Werktag is a date-intelligence MCP server for agents that need correct working-day answers, not guesses.

CORE TOOLS • is_business_day / next_business_day / previous_business_day / add_business_days / count_business_days for 251 countries and territories • Per-country weekends via CLDR (e.g. Fri–Sat in Egypt and UAE, Sun-only in India) — not a naive Sat/Sun assumption • Public holidays via the holidays library, with subdivision support (German states, US states, regions) • count_business_days returns a full breakdown: calendar days, weekend days, and each named holiday in the window • list_public_holidays for any country/year, localized English names

UNIQUE: GERMAN LEGAL DEADLINES (§§ 186–193 BGB) • calculate_legal_deadline implements German civil-law deadline rules: event vs. fixed-date deadlines (§ 187), period end and month-end clamping (§ 188), weekend/holiday shifting with the norm cited in the result (§ 193), and an explicit warning where § 193 does NOT apply (termination deadlines) • Built for contract, notice, and revocation (Widerruf) use cases — e.g. revocation received Sep 4 → deadline Sep 18, with the shift rule applied and named

QUALITY • Every tool ships complete input AND output JSON schemas • Documented, actionable error paths (invalid subdivision lists valid values, reversed date windows, timezone handling) • 61-check test suite against verified ground truth (statute texts from gesetze-im-internet.de) • Runs fully offline — no external API keys, holidays data bundled

TYPICAL AGENT QUESTIONS • "Is October 3 a business day in Germany?" • "Next business day after 5 banking days in Italy" • "When does the 14-day revocation period end if it arrives on a Friday?" • "Business days between Dec 20 and Jan 5 in the US"