Professional Four Pillars of Destiny Chart Generator
Hour Pillar
Day Pillar
Month Pillar
Year Pillar
Day Master Analysis
Understanding the Bazi Calculation Algorithm
Bazi, also known as the Four Pillars of Destiny, is a Chinese metaphysical system used to analyze a person's destiny and personality based on their birth timing. The algorithm converts a Gregorian birth date into four pairs of "Heavenly Stems" and "Earthly Branches."
How the Pillars are Calculated
Each pillar (Year, Month, Day, Hour) is represented by two characters. The algorithm relies on the Sexagenary cycle, a 60-combination sequence of the Five Elements (Wood, Fire, Earth, Metal, Water) and the Twelve Zodiac animals.
Year Pillar: Derived from the 60-year cycle. It represents your ancestral heritage and external persona.
Month Pillar: Calculated based on the solar terms (Jie Qi). It represents your childhood, parents, and career environment.
Day Pillar: The "Day Master" (upper character) is the most critical part of the chart, representing the self.
Hour Pillar: Calculated based on the 12 double-hours of a day. It represents your internal thoughts and children.
The Five Elements and Their Roles
The Bazi algorithm doesn't just produce characters; it identifies the balance of elements in your life. For example, if your Day Master is "Geng Metal" born in the height of Summer (Fire season), the Fire "melts" the Metal, suggesting a chart that may need Water for balance.
Practical Example
If someone is born on October 15, 1990, at 14:30:
Pillar
Stem
Branch
Year
Geng (Metal)
Wu (Horse)
Month
Bing (Fire)
Xu (Dog)
Day
Gui (Water)
Si (Snake)
function calculateBazi() {
var birthDateInput = document.getElementById('birthDate').value;
var birthHour = parseInt(document.getElementById('birthHour').value);
if (!birthDateInput) {
alert("Please enter a valid birth date.");
return;
}
if (isNaN(birthHour) || birthHour 23) {
birthHour = 0; // Default to midnight if invalid
}
var dateParts = birthDateInput.split('-');
var year = parseInt(dateParts[0]);
var month = parseInt(dateParts[1]);
var day = parseInt(dateParts[2]);
var stems = ["Jia (Yang Wood)", "Yi (Yin Wood)", "Bing (Yang Fire)", "Ding (Yin Fire)", "Wu (Yang Earth)", "Ji (Yin Earth)", "Geng (Yang Metal)", "Xin (Yin Metal)", "Ren (Yang Water)", "Gui (Yin Water)"];
var branches = ["Zi (Rat)", "Chou (Ox)", "Yin (Tiger)", "Mao (Rabbit)", "Chen (Dragon)", "Si (Snake)", "Wu (Horse)", "Wei (Goat)", "Shen (Monkey)", "You (Rooster)", "Xu (Dog)", "Hai (Pig)"];
// Year Pillar Logic
var yearStemIdx = (year – 3) % 10;
if (yearStemIdx <= 0) yearStemIdx += 10;
var yearBranchIdx = (year – 3) % 12;
if (yearBranchIdx <= 0) yearBranchIdx += 12;
// Day Pillar Logic (Using Julian Day Number for accuracy)
var a = Math.floor((14 – month) / 12);
var y = year + 4800 – a;
var m = month + 12 * a – 3;
var jdn = day + Math.floor((153 * m + 2) / 5) + 365 * y + Math.floor(y / 4) – Math.floor(y / 100) + Math.floor(y / 400) – 32045;
// Day calculation based on reference date (JDN of Jan 1, 1900 is 2415021)
// Pillar 11 (Jia Xu) was Jan 1, 1900
var dayPillarIdx = (jdn – 2415021 + 10) % 60;
var dStemIdx = dayPillarIdx % 10;
var dBranchIdx = dayPillarIdx % 12;
// Month Pillar Logic (Approximation based on Gregorian months for logic demo)
// In actual Bazi, this requires solar term calculations (Jie Qi)
var mBranchIdx = (month + 1) % 12;
var mStemIdx = ((yearStemIdx % 5) * 2 + mBranchIdx) % 10;
// Hour Pillar Logic
var hBranchIdx = Math.floor((birthHour + 1) / 2) % 12;
var hStemIdx = ((dStemIdx % 5) * 2 + hBranchIdx) % 10;
// Update UI
document.getElementById('yearStem').innerText = stems[yearStemIdx – 1] || stems[9];
document.getElementById('yearBranch').innerText = branches[yearBranchIdx – 1] || branches[11];
document.getElementById('monthStem').innerText = stems[mStemIdx];
document.getElementById('monthBranch').innerText = branches[mBranchIdx];
document.getElementById('dayStem').innerText = stems[dStemIdx];
document.getElementById('dayBranch').innerText = branches[dBranchIdx];
document.getElementById('hourStem').innerText = stems[hStemIdx];
document.getElementById('hourBranch').innerText = branches[hBranchIdx];
// Day Master Analysis
var dmName = stems[dStemIdx];
var interpretation = "";
if (dmName.includes("Wood")) interpretation = "Your Day Master is Wood. You are likely growth-oriented, kind, and creative. Like a tree, you seek to expand your horizons.";
else if (dmName.includes("Fire")) interpretation = "Your Day Master is Fire. You are passionate, expressive, and optimistic. You bring warmth and light to those around you.";
else if (dmName.includes("Earth")) interpretation = "Your Day Master is Earth. You are stable, nurturing, and reliable. People look to you for support and grounding.";
else if (dmName.includes("Metal")) interpretation = "Your Day Master is Metal. You are disciplined, focused, and possess strong principles. You value justice and efficiency.";
else if (dmName.includes("Water")) interpretation = "Your Day Master is Water. You are intelligent, flexible, and intuitive. Like a river, you can adapt to any environment.";
document.getElementById('dayMasterText').innerText = interpretation;
document.getElementById('baziResult').style.display = 'block';
}