Chinese Almanac （每日黃曆）

Lunar date, ganzhi pillars and the traditional daily markers — computed entirely in your browser by the same WASM kernel that powers the public API.

Pick a date to see its almanac. The page itself makes zero network requests after load.

Date（日期，Beijing time）

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Two systems, printed side by side — and why they never agree

The 建除（jiànchú）twelve day officers and the 黃道黑道（huángdào hēidào）twelve yellow/black spirits are independent systems. They are both anchored to the month branch and the day branch, but their assignment rules are mathematically incompatible. The tradition itself says so: the editors of the 《協紀辨方書》 (Qing imperial almanac compendium, ch. 7) noted that pairing them 「萬不能與建除相合」 — "can never be made to agree" — and called attempts to force a mapping "evasive wordwork". This page reports both as computed and takes no side; what "auspicious" means depends on which system (and which school) you ask.

A third daily marker, 六曜（liùyào，大安/赤口/先勝…）, is a later folk layer with its own convention; and the Purple-White stars （紫白） have several incompatible derivations — where our kernel refuses to output a value the literature leaves genuinely ambiguous (the day Purple-White star), it says so explicitly instead of guessing.

How this is computed

Lunar date and leap months: new-moon chain + GB/T 33661-2017 leap rules, cross-checked against the Hong Kong Observatory 1901–2100 (99.88% month starts, all divergences attributed).
Year/month pillars flip at the exact Lichun/jie instants; the day pillar uses the civil (midnight) boundary. Other conventions are available on the chart verifier and in the API.
The same numbers are served by the public GET /v1/calendar?date=YYYY-MM-DD endpoint — same kernel binary, byte-identical output.

Boundary note: all fields use Beijing time (UTC+8). Pre-1929 historical almanacs used Beijing Local Mean Time for the civil date — that is why some old almanacs differ by one day from this page in a handful of near-midnight years.