# China Calendar & ID Check API: holidays, 调休 workdays, lunar dates, solar terms, USCC and resident ID validation

Mainland China statutory holidays and 调休 make-up workdays, from official State Council (国务院办公厅) notices.
Supported years: 2025, 2026. 2027: not yet published by the State Council (will be added after the notice, usually in November).

Paid endpoints (0.01 USDC each, x402 v2, scheme "exact", network eip155:8453, payTo 0xA94AaF06ad79baD31E0DF25187d376780a8836c6):
  GET https://cn-holiday-x402.linholiday.workers.dev/is-workday?date=YYYY-MM-DD
  GET https://cn-holiday-x402.linholiday.workers.dev/holidays?year=YYYY
  GET https://cn-holiday-x402.linholiday.workers.dev/lunar?date=YYYY-MM-DD      Chinese lunar date (农历), ganzhi, zodiac, solar term, festivals (1902-2098)
  GET https://cn-holiday-x402.linholiday.workers.dev/solar-terms?year=YYYY      24 solar terms (节气) with exact UTC+8 times (1902-2098)
  GET https://cn-holiday-x402.linholiday.workers.dev/validate/uscc?code=XXXXXXXXXXXXXXXXXX        Unified Social Credit Code (统一社会信用代码) check character, authority, org type, region
  GET https://cn-holiday-x402.linholiday.workers.dev/validate/cn-resident-id?id=XXXXXXXXXXXXXXXXXX  Resident ID (身份证号) check digit, province, birthdate, age, gender
  (Validators are offline structural/checksum checks; they do not confirm the entity or person exists. Inputs are not stored.)
Free previews (fixed sample input): /preview/is-workday /preview/holidays /preview/lunar /preview/solar-terms /preview/uscc /preview/cn-resident-id
Requests without payment get the x402 402 challenge. Invalid dates or unsupported years return HTTP 400 and the payment is NOT settled, so you are never charged for an error.

Free: GET /health, GET /openapi.json, GET /.well-known/x402, GET /llms.txt

Sources:
  2025: 国务院办公厅关于2025年部分节假日安排的通知 (国办发明电〔2024〕12号) https://www.gov.cn/zhengce/zhengceku/202411/content_6986383.htm
  2026: 国务院办公厅关于2026年部分节假日安排的通知 (国办发明电〔2025〕7号) https://www.gov.cn/zhengce/zhengceku/202511/content_7047091.htm

Lunar calendar and solar terms are computed with the open-source lunar-javascript library (MIT).

Disclaimer: holidays are transcribed from the official notices; local or employer-specific arrangements may differ.