# convert_solar_to_lunar Use this when you need the Chinese lunar date, ganzhi day/month/year, zodiac year or current solar term for a given Gregorian date (defaults to today). Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when you start from a lunar date and need the Gregorian date (use lunar-to-solar), need a person's zodiac with the 立春 boundary option (use chinese-zodiac), or need the astronomical moon phase (use moon-phase). What it computes: Converts a Gregorian date to the Chinese lunisolar calendar (农历 nongli): lunar year, month (with leap-month flag), day, the sexagenary stems and branches (干支 ganzhi) of year, month and day, zodiac animal, nayin (纳音), the current 24-solar-term period and any traditional festival on that day. Example user requests: Convert 2026-09-25 to the Chinese lunar calendar and say whether it is a leap month. | 把 2025-07-25 换成农历，并给出干支和节气。 | Which Chinese lunar festival falls on this Gregorian date? Inputs: date (date, optional). Complete JSON argument examples: {"date":"2026-09-24"} | {"date":"2025-07-25"} Outputs: lunar_year, lunar_month, is_leap_month, lunar_day, lunar_date_chinese, lunar_date_text, month_name, day_name, month_days, leap_month_this_year, year_ganzhi, year_ganzhi_pinyin, year_english, zodiac, nayin_year, month_ganzhi, month_ganzhi_pinyin, day_ganzhi, day_ganzhi_pinyin, weekday, current_solar_term, next_solar_term, days_to_next_term [days], is_solar_term_day, festival, julian_day_number. Formula: lunar month = interval between successive new moons (instants at 120° E, UTC+8); month 11 contains the winter solstice; a leap month is the first month without a major solar term (中气) in a 13-month solstice-to-solstice suite; year_ganzhi index = (lunar_year − 4) mod 60; day_ganzhi index = (JDN + 49) mod 60; month branch = 寅 from 立春, one branch per odd solar term Direct REST fallback: POST https://tttkmbb.com/api/v1/calculate/lunar-calendar-converter with the same JSON input fields. Do not guess another /api/* path. Docs: https://tttkmbb.com/lunar/lunar-calendar-converter.md Agent View of the PolicyLayer registry record for `convert_solar_to_lunar`. HTML page: https://policylayer.com/tools/com-tttkmbb-calcgrid/convert-solar-to-lunar ## Facts - Tool: `convert_solar_to_lunar` - Server: Calcgrid (`https://tttkmbb.com/mcp`) — https://policylayer.com/tools/com-tttkmbb-calcgrid.md - Homepage: https://github.com/https://tttkmbb.com/mcp - Risk category: Write (Medium risk) - Registry record: grade D, identity unverified - Server auth posture: open - Server CORS policy: * - Server rate-limited: no - Parameters: 1 - Recommended policy verdict: Rate-limited ## Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | `date` | string | no | Civil date in China Standard Time (UTC+8), 1900–2100; defaults to the current UTC date. | Parameters from the server's own tool schema. ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "convert_solar_to_lunar", "arguments": {} } } ``` ## Why convert_solar_to_lunar is rated Medium An AI agent can call convert_solar_to_lunar faster than any human can review: one bad instruction and it creates or modifies resources in Calcgrid by the hundred, each call as confident as the last. ## Use case AI agents use convert_solar_to_lunar to create or update resources in Calcgrid, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Calcgrid environment. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Calcgrid: ```json { "version": "1", "default": "deny", "tools": { "convert_solar_to_lunar": { "limits": [ { "counter": "convert_solar_to_lunar_rate", "window": "minute", "max": 30, "scope": "grant" } ] } } } ``` ## Other tools on Calcgrid (252) - `calculate_bazi_four_pillars` — Execute — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-bazi-four-pillars.md - `run_calculator` — Execute — https://policylayer.com/tools/com-tttkmbb-calcgrid/run-calculator.md - `calculate_ab_test_significance` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-ab-test-significance.md - `calculate_age` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-age.md - `calculate_bmi` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-bmi.md - `calculate_bmr` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-bmr.md - `calculate_circle_properties` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-circle-properties.md - `calculate_compound_interest` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-compound-interest.md - `calculate_depth_of_field` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-depth-of-field.md - `calculate_haversine_distance` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-haversine-distance.md - `calculate_kinetic_energy` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-kinetic-energy.md - `calculate_loan_payment` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-loan-payment.md - `calculate_molar_mass` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-molar-mass.md - `calculate_mortgage_payment` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-mortgage-payment.md - `calculate_percentage` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-percentage.md - `calculate_percentage_change` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-percentage-change.md - `calculate_running_pace` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-running-pace.md - `calculate_subnet` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-subnet.md - `calculate_t_test` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-t-test.md - `calculate_tdee` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/calculate-tdee.md - `cast_plum_blossom_hexagram` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/cast-plum-blossom-hexagram.md - `check_ar_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-ar-working-day.md - `check_at_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-at-working-day.md - `check_australia_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-australia-working-day.md - `check_bd_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-bd-working-day.md - `check_be_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-be-working-day.md - `check_bg_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-bg-working-day.md - `check_br_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-br-working-day.md - `check_canada_federal_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-canada-federal-working-day.md - `check_ch_working_day` — Read — https://policylayer.com/tools/com-tttkmbb-calcgrid/check-ch-working-day.md - …and 222 more: https://policylayer.com/tools/com-tttkmbb-calcgrid.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=com-tttkmbb-calcgrid · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-tttkmbb-calcgrid