Four Pillars first, then the shape of a whole life
Jade Almanac turns a birth date, sex, and optional birth time into the Four Pillars, Day Master, strength balance, favorable elements, and ten-year luck pillars. It then scores the years across an eighty-year span and draws them as a candlestick-style life chart. Each candle can be opened to show the element arriving that year, its effect on the Day Master, and the decade context around it.
Birth time is optional. When it is missing, the calculator drops the hour pillar instead of silently guessing noon, and renormalizes the strength calculation as a three-pillar chart. Adding a birth city lets the tool correct the recorded clock time for longitude and daylight saving; without a city, it uses the literal clock time and warns when a two-hour pillar boundary is close.
The arithmetic is part of the product
The methodology page publishes a versioned v1.0 specification for the entire calculation. It names the Li Chun year boundary, solar-term month pillars, five-tigers and five-rats rules, position weights for Day Master strength, hidden-stem shares, favorable-element rule, luck-pillar offsets, yearly scoring, and the branch relations used for candle wicks.
That transparency also makes the limits unusually clear. Jade Almanac describes the result as one simplified strengthen-and-balance school, flags near-balanced charts, and records a known single-year miss in its own public example. The chart is presented as cultural interpretation and entertainment rather than a medical, legal, or financial forecast.
Free, no account, with a visible privacy tradeoff
The calculator is free and does not ask for an account. The site says birth inputs are used for the calculation and are not stored in its database. Results are carried in the page URL, however, so dates can remain in the user's browser history and are visible to anyone who receives a shared result link.
