compute_birth_chart
Cast a natal birth chart
Casts a natal chart: each planet's sign and exact degree in both the tropical (Western) and sidereal (Vedic, Lahiri) zodiacs, the ascendant, the twelve Placidus cusps, the midheaven, retrograde state and the Moon's nakshatra. It covers any chart, rising sign, Moon sign or planet-in-house. Takes a birth date (1800-2200) and a place.
The chart uses the UTC offset in force at that place on that date (East Tennessee kept Central time until 1947), and an hour's error moves the ascendant about 15 degrees, usually into another sign, with the houses following. With "time" left out for an unknown birth time, the ascendant, cusps and houses are withheld, because a stand-in time such as noon gives a wrong ascendant.
Results include an attribution line and a permalink.
输入参数tzlatlondate必填timeplace
compute_maya_day_sign
Convert a date to the Maya calendars
Converts a Gregorian date to the Maya calendars: Tzolk'in day sign and tone as written (e.g. "6 Oc"), kin 1-260, the sign's meaning, direction and trecena, the Haab date, the Long Count and the Julian Day Number. It covers a Maya day sign or birth sign, or any event's Maya date.
The method is the Julian Day Number minus a correlation constant, then remainders mod 20, 13, 260 and 365, where an off-by-one gives a real day sign that is the wrong one. Which constant to use is the open argument in Maya calendrics: this uses Goodman-Martinez-Thompson 584283 and returns it. Time of day, place and zone play no part.
Results include an attribution line and a permalink.
输入参数date必填
compute_tarot_birth_card
Work out a tarot birth card
Reduces a birth date to its tarot birth card by this site's own rule, with 11, 22 and 33 held as master numbers, returning the card, its Roman numeral and every step of the arithmetic. It covers a birth, life or destiny card. The date alone decides it.
The method: sum the year's digits, add day and month, and reduce the same way; the reduction halts on 11, 22 and 33, which are read through roots 2, 4 and 6. 1993 sums to 22 and stops there; reducing on to 4 gives another card. Root 8 is Strength in the Rider-Waite-Smith numbering used here, and Justice in Marseille packs.
The rule is a twentieth-century convention found in no early tarot source.
Results include an attribution line and a permalink.
输入参数date必填
convert_calendar_date
Convert a date between calendars
Converts between the Gregorian and Julian calendars, the Julian Day Number and the three Maya counts (Tzolk'in, Haab, Long Count), any one to all the others, and searches a year range for a Calendar Round ("when was 4 Ahau 3 Kankin"). Takes exactly one starting point: a Gregorian date, a jdn, a longcount, a julian date, or a round with from and to. Two are refused.
Every conversion passes through the Julian Day Number, a single count of days. The Gregorian and Julian calendars drift apart by a different number of days each century (ten at the 1582 reform, thirteen now), and pre-reform dates are often quoted as Julian without saying so. A Calendar Round repeats every 18,980 days. States the Goodman-Martinez-Thompson constant 584283.
Results include an attribution line and a permalink.
输入参数tojdndatefromroundjulianlongcount
compute_panchang
Read the panchang for a date and place
Computes the panchang for one civil date at one place: tithi, nakshatra with pada, yoga and karana, each with the UTC and local instants it begins and ends, plus vara, sunrise, sunset, day length and the lunar month (amanta and purnimanta). Takes a place, or lat and lon.
A tithi is the interval in which the Moon gains twelve degrees on the Sun, 20-26.8 hours (mean 23.6), and the civil day it names is set by the tithi running at that place's sunrise, so two cities' panchangs for one date can differ by a whole tithi. Nakshatra about 20.8 to 27.2 hours, yoga about 19.5 to 25.2 hours, karana about 10 to 13.4 hours. A latitude with no sunrise that day is refused.
Results include an attribution line and a permalink.
输入参数tzlatlondateplace
compute_moon_phase
Get the Moon's phase and the lunation's exact times
Returns the Moon's phase at an instant: phase angle, illuminated fraction, the eight-fold name, waxing or waning, age in days, tropical sign and degree, distance, and the four principal phases of that lunation to the second in UTC; optionally every principal phase across a date range.
A count of days from one new moon in steps of 29.53 follows the mean month, and a real new moon can fall more than half a day from the mean one; the gap is widest at the quarters and the full moon. Phase names follow Moon-Sun elongation. The phase changes within a day, so the hour matters; "time" is UTC and defaults to 00:00.
Results include an attribution line and a permalink.
输入参数todatetime
find_eclipses
Find the eclipses near a date
Finds the solar and lunar eclipses nearest a date: greatest eclipse to the second in UTC, type, obscuration, the eclipsed body's sign, days from the date, and for a solar eclipse where greatest eclipse meets the Earth. Given a place, each listing also carries what that observer gets: local kind, first contact, maximum, last contact and altitude at each.
The 6,585.3-day saros groups eclipses into families whose members fall about a year or a continent apart, and a global eclipse is seen from only part of the Earth. Global and local circumstances are kept apart, including the Moon setting partway through or rising with the eclipse underway.
Results include an attribution line and a permalink.
输入参数tzlatlondatecountplacefamily
check_retrogrades
Check which planets are retrograde, and until when
Reports which planets are retrograde on a date and the two stations that open and close each body's current period ("since 2026-02-14, until 2026-03-07"). Per body: retrograde flag, ecliptic longitude, longitude speed, sign and degree, and both stations with exact UTC instants.
The dates shift every cycle and follow no fixed calendar rule; Mercury stations retrograde three or four times a year. A station is where longitude speed crosses zero, found by bisection for eight bodies, so this takes longer than a single-instant position.
Excluded: the Sun and Moon, which cannot station, and Rahu and Ketu, whose mean motion is backwards throughout. The "excluded" array lists them.
Results include an attribution line and a permalink.
输入参数datetime
compute_vimshottari_dasha
Compute a Vimshottari dasha timeline
Computes the Vimshottari dasha timeline from a birth date, time and place: all nine mahadashas of the 120-year cycle, each with the exact instant it opens and closes, the balance at birth in years, months and days, the Moon's nakshatra and pada that fix the sequence, and the nine antardashas inside the mahadasha running on the "asof" date (the birth, when it is absent). The answer does not depend on the server clock, so it stays citable at a stable permalink.
The whole table hangs off one number, the Moon's sidereal longitude at the birth instant. The nakshatra it falls in names the first lord, and the share of that nakshatra still to be crossed, times the lord's years, is the balance at birth. A tenth of a degree moves the balance by weeks and every later boundary with it; a few degrees changes which planet the cycle opens with.
"time" is required here: the Moon covers about 13.2 degrees a day against a nakshatra 13 degrees 20 minutes wide, so an unknown birth time means an unknown first lord. Without it the call returns a "time_required" refusal. The cycle runs Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn and Mercury, for 7, 20, 6, 10, 7, 18, 16, 19 and 17 years.
Three conventions come back in the result and are where two programs disagree about one chart: result.ayanamsa, result.yearLengthDays, result.origin.utcInstant. Against Drik Panchang every boundary here falls 1.70 days earlier; result.conventionNote explains the difference.
Results include an attribution line and a permalink.
输入参数tzlatlonasofdate必填time必填place必填
compute_transits
Find the transits to a birth chart on a date
Computes where the sky is on a chosen date against where it was at somebody's birth: ten transiting bodies with longitude, sign, degree, speed and retrograde state, and every aspect they make to the natal planets and angles, each with its orb, the orb allowed, the natal longitude measured against, and whether the contact is applying or separating. It covers what is transiting a chart, whether a transit is active on a date, a Saturn return, or whether a contact has perfected.
The computation takes two full sets of ecliptic longitudes (the birth instant, at the historic UTC offset of that place and date, and the target instant), then the angle between every pair taken the short way round the circle: about a hundred and fifty separations, each with a wrap case at 0 Aries. A contact is applying when its orb shrinks over the following hour, and separating when it grows.
The orb convention is in result.orbConvention. How close a transit has to be to count is a convention, and an aspect list without its orb cannot be checked. Here: 3 degrees for conjunction, opposition, trine and square, 2 for sextile, deliberately tighter than a natal chart's 8.
With "time" left out for an unknown birth time, the ascendant and midheaven are dropped entirely, because a transit to an angle cast for an arbitrary noon has no meaning. The Moon is included, where most software excludes it; the lunar nodes are excluded. Significance is interpretation and is not computed here.
Results include an attribution line and a permalink.
输入参数aton必填tzlatlondate必填timeplace必填
get_planetary_positions
Get every planet's position on a date
Returns where every body is at an instant, with no birth data and no place required: Sun, Moon, the eight planets and the two lunar nodes, each with geocentric ecliptic longitude, sign and degree in both the tropical (Western) and sidereal (Vedic) zodiacs, ecliptic latitude, longitude speed in degrees per day, retrograde state and distance. It covers "what sign is Venus in", "where is Mercury right now", "what sign is the Moon in today", "when did Mars enter Gemini": any position question about the sky with no particular person's chart in it.
A geocentric longitude is identical for every observer on Earth, so a sky question needs no birthplace and no chart. An observer's lat and lon are used only for rise and set times.
A planet sits within a degree of a cusp for days, so "Venus is in Scorpio" can be true on Tuesday and false on Wednesday; the Moon moves about half a degree an hour and changes sign roughly every 2.3 days, so its row depends on the hour as well as the date. "time" is UTC and defaults to 00:00.
Both zodiacs come back in every row: result.bodies[].sign is the tropical sign and result.bodies[].siderealSign the sidereal one. They differ by result.ayanamsa, about 24 degrees, very nearly a whole sign, so the two are usually different signs. Rahu and Ketu are the mean nodes (result.nodeNote). result.retrogradeNow lists which of the eight stationing bodies are retrograde; the two nodes, which move backwards every day, are reported apart in result.alwaysRetrograde.
Results include an attribution line and a permalink.
输入参数tzlatlondatetimeplace
resolve_utc_offset
Historic UTC offset
Resolves the UTC offset in force at a place on a date: the IANA zone that applied then, the signed offset, the UTC instant it resolves to, and a confidence of high, best-effort or low with the reason for anything below high. A statute that moved the zone is quoted with its Federal Register citation.
The present-day zone map can give the wrong offset for a past date. Tennessee was on Central time until 28 September 1947, so a Knoxville record from that March is UTC-6 where America/New_York gives UTC-5.
Results include an attribution line and a permalink.
输入参数date必填timeplace必填
convert_chinese_lunar_date
Chinese lunar date converter
Converts a Gregorian date to the Chinese lunisolar calendar or back: lunar year, month, day, whether the month is a leap month, when it began, and the solar term in effect. Takes "date" or "lunar", one of the two.
A month starts on the day, at Beijing time, of its new moon, so tables built in another zone can put months a day off. Placement follows GB/T 33661-2017. Leap months, 2033-2035 and pre-1929 dates come back unverified, with no date.
Results include an attribution line and a permalink.
输入参数dateleaplunar
get_solar_terms
24 solar terms of a year
Returns the 24 solar terms of a "year" (1926-3026): the instant the Sun reaches each 15-degree mark of ecliptic longitude, in UTC, Beijing time and an optional zone, each with its uncertainty band in seconds.
A term's date depends on the clock it is read in, and fixed-date lists can be a day off either way. A year whose band touches a midnight comes back unverified, with no dates.
Results include an attribution line and a permalink.
输入参数tzyear
compute_four_pillars
Four pillars (bazi) of a birth
Computes the four pillars (bazi) of a birth: the stem and branch of the year, month, day and hour, and each pair's place in the sixty cycle. Stems and branches only, no interpretation. Takes "date", "time" and "place".
The month changes at the solar terms, and the hour needs the birthplace's historic UTC offset. Without a birth time the call returns a time_required refusal.
Results include an attribution line and a permalink.
输入参数date必填time必填place必填
get_iching_hexagram_text
I Ching hexagram text, cited
Returns one of the 64 Zhouyi (I Ching) hexagrams by "hexagram" number: trigrams, lines, and the judgement text (and one line text if asked) as printed in an edition with a preface dated 1591, each column with its archive page locator. Text not confirmed against a second copy is withheld.
The English meaning is AI-written and labelled; no human scholar has checked it. Each quoted column carries its archive locator.
Results include an attribution line and a permalink.
输入参数linehexagram必填
compute_heluo_birth_hexagram
He Luo birth hexagram, with its held-out result
Computes the He Luo birth hexagram from "date", "time" and "place": the hexagram the He Luo Zhen Shu (preface dated 1591) counts from the four pillars, as the book reads a man's chart, a woman's, or both (read_as), with each rule's basis and locator. No interpretation.
Held-out test failed: 1 of 4 sealed book charts passed; 1 of 3 scored contradicts the stated rules. result.validation states this beside the hexagram.
Results include an attribution line and a permalink.
输入参数date必填time必填place必填read_as
compute_seven_governors_chart
Seven Governors chart of a birth
Computes the Chinese Seven Governors and Four Remainders chart from "date", "time" and "place": the life palace, and for the Sun, Moon, five planets, Luohou, Jidu, Yuebei and Ziqi the longitude in degrees, lodge, du and palace, plus home-palace and raised-to-hall dignities with page locators. Facts only: no reading or verdict.
The lodges are unequal in width and move with precession.
Results include an attribution line and a permalink.
输入参数date必填time必填place必填