Ascendant (Rising Sign) Calculator

ANA›Life Services Authority›National Calculator Authority›Ascendant (Rising Sign) Calculator

.calc-container { max-width: 640px; margin: 2rem 0; padding: 1.5rem; background: #fff; border: 1px solid #ddd; border-radius: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.06); font-family: system-ui, -apple-system, sans-serif; } .calc-container h3 { font-family: Georgia, serif; font-size: 1.15rem; color: #1a1a1a; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-row { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; flex-wrap: wrap; } .calc-row label { min-width: 160px; font-size: 0.9rem; color: #333; font-weight: 500; } .calc-row input[type="number"], .calc-row select { flex: 1; min-width: 120px; max-width: 200px; padding: 0.5rem 0.6rem; border: 1px solid #ccc; border-radius: 4px; font-size: 0.9rem; font-family: system-ui, sans-serif; color: #1a1a1a; background: #fafaf8; } .calc-row input:focus, .calc-row select:focus { outline: none; border-color: var(--ac, #3d5a80); box-shadow: 0 0 0 2px rgba(26,74,138,0.12); } .calc-row .unit { font-size: 0.82rem; color: #888; min-width: 30px; } .calc-btn { display: inline-block; margin-top: 0.5rem; padding: 0.55rem 1.5rem; background: var(--ac, #3d5a80); color: #fff; border: none; border-radius: 4px; font-size: 0.9rem; font-weight: 600; cursor: pointer; font-family: system-ui, sans-serif; } .calc-btn:hover { opacity: 0.9; } .calc-result { margin-top: 1.25rem; padding: 1rem 1.25rem; background: #f0f6fc; border-left: 3px solid var(--ac, #3d5a80); border-radius: 0 6px 6px 0; display: none; } .calc-result.visible { display: block; } .calc-result-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: #666; margin-bottom: 0.25rem; } .calc-result-value { font-size: 1.6rem; font-weight: 700; color: var(--ac, #3d5a80); } .calc-result-detail { font-size: 0.85rem; color: #555; margin-top: 0.5rem; line-height: 1.5; } .calc-note { margin-top: 1rem; font-size: 0.8rem; color: #888; font-style: italic; } .calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin-top: 0.75rem; } .calc-grid-item { padding: 0.6rem 0.8rem; background: #f8f9fa; border-radius: 4px; border: 1px solid #eee; } .calc-grid-item .label { font-size: 0.75rem; color: #888; text-transform: uppercase; letter-spacing: 0.04em; } .calc-grid-item .value { font-size: 1.1rem; font-weight: 600; color: #1a1a1a; } @media (max-width: 720px) { .calc-row { flex-direction: column; align-items: flex-start; gap: 0.3rem; } .calc-row label { min-width: auto; } .calc-row input[type="number"], .calc-row select { max-width: 100%; width: 100%; } .calc-grid { grid-template-columns: 1fr; } } .calc-chart { margin: 1rem 0; text-align: center; } .calc-chart svg { max-width: 100%; height: auto; } .calc-chart-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.6rem 1.2rem; margin-top: 0.6rem; font-size: 0.8rem; color: #555; } .calc-chart-legend span { display: inline-flex; align-items: center; gap: 0.3rem; } .calc-chart-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; font-style: normal; } .calc-related { max-width: 640px; margin: 2rem 0 1rem; padding: 1.25rem 1.5rem; background: #f8f9fa; border: 1px solid #e8e8e8; border-radius: 8px; } .calc-related h3 { font-family: Georgia, serif; font-size: 1rem; color: #1a1a1a; margin: 0 0 0.75rem; padding-bottom: 0.4rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-related-list { list-style: none; padding: 0; margin: 0 0 0.75rem; display: grid; grid-template-columns: 1fr 1fr; gap: 0.4rem 1.5rem; } .calc-related-list li a { font-size: 0.88rem; color: var(--ac, #3d5a80); text-decoration: none; } .calc-related-list li a:hover { text-decoration: underline; } .calc-browse-all { margin: 0.5rem 0 0; font-size: 0.9rem; font-weight: 600; } .calc-browse-all a { color: var(--ac, #3d5a80); text-decoration: none; } .calc-browse-all a:hover { text-decoration: underline; } @media (max-width: 720px) { .calc-related-list { grid-template-columns: 1fr; } }

Ascendant (Rising Sign) Calculator

Calculate your Ascendant (Rising Sign) — the zodiac sign rising on the eastern horizon at the exact moment of your birth. An accurate birth time and location are essential.

Birth Date

Birth Time (local time)

Birth Latitude (°, negative = South)

Birth Longitude (°, negative = West)

UTC Offset at Birth (hours, e.g. -5 for EST)

Calculate Ascendant

function ascCalc() { const resultDiv = document.getElementById('asc-result'); resultDiv.innerHTML = '';

const dateStr = document.getElementById('asc-birth-date').value; const timeStr = document.getElementById('asc-birth-time').value; const latVal = document.getElementById('asc-lat').value; const lonVal = document.getElementById('asc-lon').value; const tzVal = document.getElementById('asc-tz').value;

// --- Validation --- if (!dateStr) { resultDiv.innerHTML = 'Please enter a birth date.'; return; } if (!timeStr) { resultDiv.innerHTML = 'Please enter a birth time.'; return; } if (latVal === '') { resultDiv.innerHTML = 'Please enter a birth latitude.'; return; } if (lonVal === '') { resultDiv.innerHTML = 'Please enter a birth longitude.'; return; } if (tzVal === '') { resultDiv.innerHTML = 'Please enter a UTC offset.'; return; }

const lat = parseFloat(latVal); const lon = parseFloat(lonVal); const tz = parseFloat(tzVal);

if (isNaN(lat) || lat 90) { resultDiv.innerHTML = 'Latitude must be between -90 and 90.'; return; } if (isNaN(lon) || lon 180) { resultDiv.innerHTML = 'Longitude must be between -180 and 180.'; return; } if (isNaN(tz) || tz 14) { resultDiv.innerHTML = 'UTC offset must be between -12 and +14.'; return; } if (Math.abs(lat) > 66.5) { resultDiv.innerHTML = 'Ascendant calculation is unreliable above the Arctic/Antarctic circles (|lat| > 66.5°).'; return; }

// --- Parse date/time --- const [year, month, day] = dateStr.split('-').map(Number); const [hour, minute] = timeStr.split(':').map(Number);

// Convert local time to UT const localDecimalHour = hour + minute / 60.0; const utHour = localDecimalHour - tz;

// --- Julian Day Number (JDN) for UT --- // Using the standard astronomical formula let Y = year, M = month, D = day; const decDay = D + utHour / 24.0; if (M = 0 && LSTnorm = 180) ascDeg -= 180; } else if (LSTnorm >= 90 && LSTnorm = 180 && LSTnorm

#### Formula

1. Julian Day Number (JD) JD = ⌊365.25(Y+4716)⌋ + ⌊30.6001(M+1)⌋ + D + B − 1524.5 where B = 2 − ⌊Y/100⌋ + ⌊⌊Y/100⌋/4⌋ (Gregorian correction), and D includes the fractional UT hour.

2. Greenwich Mean Sidereal Time (GMST) T = (JD − 2451545.0) / 36525 GMST = 280.46061837 + 360.98564736629 × (JD − 2451545) + 0.000387933T² − T³/38710000 (degrees)

3. Local Sidereal Time (LST) LST = GMST + Geographic Longitude (degrees)

4. Obliquity of the Ecliptic (ε) ε = 23.439291111° − 0.013004167°·T − 0.0000001639°·T² + 0.0000005036°·T³

5. Ascendant Ecliptic Longitude ASC = arctan(−cos(LST) / (sin(ε)·tan(φ) + cos(ε)·sin(LST))) where φ = geographic latitude. Quadrant correction applied based on LST quadrant.

6. Zodiac Sign Sign = ⌊ASC / 30⌋ → index into the 12 zodiac signs (Aries = 0°, Taurus = 30°, … Pisces = 330°)

#### Assumptions & References

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References

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