Methodology
Methodology and Sources
Where the dates come from, how a sign is derived from them, and the line between a calculated fact and a traditional interpretation.
The calendar source
Chinese New Year boundaries come from the Hong Kong Observatory Gregorian-Lunar Calendar Conversion Table, covering 1901–2100. The table is checked into this site as a fixture and validated in the build, so the published calculator makes no third-party request at runtime and its answers cannot change because an external service changed.
Complete zodiac-year intervals therefore run from 1901-02-19 through 2100-02-08. Dates outside that range are refused rather than estimated.
How a sign is derived
A zodiac year runs from one Chinese New Year to the day before the next. A birth date is compared against that year's boundary: on or after it, the date belongs to that zodiac year; before it, to the previous one. This is why a January or early-February birth date often carries the previous animal.
The animal comes from the twelve-year branch cycle and the element and polarity from the ten-stem cycle, which together produce the sixty-year Gan-Zhi name such as Yang Wood Dragon.
A note on other boundary conventions
This site uses the lunar New Year boundary throughout. Some Four Pillars and BaZi traditions instead begin the year at the solar term Li Chun, around 4 February, which can place a birth date in a different animal year. That is a different method rather than a correction to this one, and results here should not be compared directly against it.
Calculated facts and traditional interpretation
Calculated from the source table: the animal, the element and Yin or Yang polarity, the Gan-Zhi name, the zodiac year, and the exact start and end dates of any year.
Traditional interpretation, presented for education and entertainment: the personality traits on each sign guide, the compatibility and conflict groupings, the customs around a person's own zodiac year, and the legends. These are cultural material, not findings, and nothing on this site is a prediction or advice of any kind.
Corrections
Calendar accuracy is the load-bearing claim here. If a boundary date on this site disagrees with the published conversion table, that is a defect worth reporting rather than a matter of interpretation. Send it to the maintainers with the page address and the input you used.