CJK Calendar Converter

Convert between East Asian lunisolar calendars (Chinese, Japanese, Korean, Vietnamese) and Gregorian/Julian dates. All conversions run locally against a SQLite database — no network calls after setup.

When to Use

• Converting a CJK era date to Gregorian (e.g., 崇禎三年四月初三 → 1630-05-14)
• Converting a Gregorian date to concurrent CJK era dates
• Looking up era metadata (date ranges, dynasties, emperors)
• Computing sexagenary cycle (干支) for a given date
• Working with Julian Day Numbers (JDN)
• Japanese era shorthand for lunisolar Meiji dates (M1.9.8 to M5.12.2, e.g. M2.1.1)

Setup

Download the SQLite database (~14 MB) on first use: