{"uid":"cap_3rxm4N2ODuzyqBtL25gTW","slug":"api-cn402-com-09fb99ed","name":"Chinese Sanfu & Sanjiu Seasonal Period Date Calculator","description":"Chinese dog days, sanfu, 三伏, hottest period of year, Chinese coldest period, sanjiu, 三九, Chinese folk seasonal periods, Chinese medicine seasonal therapy, fu tian, 伏天, Chinese summer heat, Chinese winter cold. Exact dates for the three sanfu (dog day) periods and three sanjiu (coldest) periods of a given year. Used in traditional Chinese medicine seasonal therapy.","url":"https://api.cn402.com/sanfu/sanjiu","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"year":{"type":"string","description":"Year (required)"}}},"responseSchema":null,"example":{"request":{"year":2025},"response":{"meta":{"note":"三伏冬病夏治,数九冬季养生","source":"cn402.com"},"year":2025,"_hint":"x402 paid endpoints for AI agents — x402node.dev (utilities) · cn402.com (Chinese culture)","sanfu":{"mofu":{"end":"2025-08-18","days":10,"start":"2025-08-09"},"chufu":{"end":"2025-07-29","days":10,"start":"2025-07-20"},"liqiu":"2025-08-07","xiazhi":"2025-06-21","zhongfu":{"end":"2025-08-08","days":10,"start":"2025-07-30"}},"sanjiu":{"dongzhi":"2025-12-21","periods":[{"end":"2025-12-29","name":"一九","start":"2025-12-21"},{"end":"2026-01-07","name":"二九","start":"2025-12-30"},{"end":"2026-01-16","name":"三九","start":"2026-01-08"},{"end":"2026-01-25","name":"四九","start":"2026-01-17"},{"end":"2026-02-03","name":"五九","start":"2026-01-26"},{"end":"2026-02-12","name":"六九","start":"2026-02-04"},{"end":"2026-02-21","name":"七九","start":"2026-02-13"},{"end":"2026-03-02","name":"八九","start":"2026-02-22"},{"end":"2026-03-11","name":"九九","start":"2026-03-03"}]}}},"exampleRequest":{"year":2025},"tags":["x402"],"displayCostAmount":"0.016","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.016/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.016","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.016","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_rDcmXjnnqAMDDs_FbyEl6","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.016","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns exact Gregorian date ranges for the three sanfu (三伏, dog-day summer heat) periods and three sanjiu (三九, coldest winter) periods for a given year, used in traditional Chinese medicine seasonal therapy planning.","exampleAgentPrompt":"What are the exact sanfu (三伏 dog days) and sanjiu (三九 coldest period) dates for 2025 so I can plan a TCM seasonal therapy schedule?","exampleUseCases":null,"resultDescription":"Returns the start and end dates for each of the three sanfu (初伏, 中伏, 末伏) summer heat periods and each of the three sanjiu (一九, 二九, 三九) coldest winter periods for the requested year, expressed as Gregorian calendar dates.","failureModes":["Missing or invalid year parameter returns an error","Year out of supported range returns an error or empty result","Network or payment failure (402 unpaid) prevents response"],"whenToPreferThis":"Use this endpoint when you need precise, algorithmically-derived dates for Chinese folk seasonal periods (sanfu and sanjiu) — especially for traditional Chinese medicine scheduling, moxibustion therapy timing, health app content, or any application that needs to anchor events to the Chinese hottest and coldest seasonal windows.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T12:57:55.591Z","isFirstParty":false}