LunarCalendar is a JavaScript library (Node‑.js and browser compatible) that provides full‑featured Chinese lunar (农历) and Gregorian calendar calculations. It can convert between solar and lunar dates, return month‑by‑month data with zodiac, ganzhi, 24 solar terms, festivals and work‑holiday markings, and even includes configurable holiday and almanac data for 1891‑2100. The package is aimed at developers building calendar, almanac or date‑picker applications for Chinese users.