{"openapi":"3.1.0","info":{"title":"Sun, Moon and Planets","version":"1.0.0","description":"Sun and Moon position, rise and set, twilight, planets, equation of time and eclipse checks. One call, one computed answer, no accounts or API keys. Machine-payable over x402.","x-guidance":"Sun, Moon and Planets: Sun and Moon position, rise and set, twilight, planets, equation of time and eclipse checks. /sun-position, /moon-position, /rise-set-sun, /rise-set-moon, /planet-positions, /planet-visibility, /equation-of-time, /eclipse-check. Each paid GET returns a computed verdict with the reasons, the source and what was NOT checked. A verdict of UNVERIFIED means a lookup failed: treat it as unknown. No account or key: pay per call in USDC over x402."},"servers":[{"url":"https://sky-calc.x402tookit.com"}],"paths":{"/eclipse-check":{"get":{"operationId":"eclipse_check","summary":"Can a solar or lunar eclipse happen at the new and full moon nearest a date? Type, ecliptic-latitude margin and syzygy times.","description":"Can a solar or lunar eclipse happen at the new and full moon nearest a date? Type, ecliptic-latitude margin and syzygy times.","tags":["eclipse","solar-eclipse","lunar-eclipse","astronomy","moon"],"parameters":[{"name":"date","in":"query","required":true,"description":"YYYY-MM-DD (UTC); the nearest new moon and full moon within about 15 days are screened","schema":{"type":"string"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"queryDate":{"type":["null","string"]},"newMoon":{"type":["null","object"],"properties":{"timeUtc":{"type":["null","string"]},"eclipse":{"type":["null","string"]},"moonEclipticLatitudeDeg":{"type":["null","number"]},"centralLimitDeg":{"type":["null","number"]},"partialLimitDeg":{"type":["null","number"]},"moonToSunDiameterRatio":{"type":["null","number"]},"moonDistanceKm":{"type":["null","number"]},"borderline":{"type":["boolean","null"]}}},"fullMoon":{"type":["null","object"],"properties":{"timeUtc":{"type":["null","string"]},"eclipse":{"type":["null","string"]},"moonEclipticLatitudeDeg":{"type":["null","number"]},"penumbralLimitDeg":{"type":["null","number"]},"umbralLimitDeg":{"type":["null","number"]},"totalLimitDeg":{"type":["null","number"]},"moonDistanceKm":{"type":["null","number"]},"borderline":{"type":["boolean","null"]}}},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"SOLAR_AND_LUNAR_POSSIBLE","summary":"Nearest new moon 2024-04-08 18:21 UTC: a total solar eclipse is geometrically possible somewhere on Earth. Nearest full moon 2024-03-25 07:00 UTC: only a penumbral lunar eclipse is possible (a faint s…","reasons":["An eclipse needs the Moon near the plane of Earth's orbit (an ecliptic node) at new moon (solar) or full moon (lunar). The screen compares the Moon's ecliptic latitude with the limits set by the Sun a…","Solar limits: below pi_moon + s_sun + s_moon - pi_sun some partial eclipse; below pi_moon - pi_sun the Moon's axis hits Earth (total if the Moon looks bigger than the Sun, else annular). Lunar limits …","…1 more"],"queryDate":"2024-04-08","newMoon":{"timeUtc":"2024-04-08T18:21:15Z","eclipse":"TOTAL","moonEclipticLatitudeDeg":0.3499,"centralLimitDeg":1.0133,"partialLimitDeg":1.556,"moonToSunDiameterRatio":1.0399,"moonDistanceKm":359810.1468,"borderline":false},"fullMoon":{"timeUtc":"2024-03-25T07:00:48Z","eclipse":"PENUMBRAL","moonEclipticLatitudeDeg":0.9609,"penumbralLimitDeg":1.4401,"umbralLimitDeg":0.8951,"totalLimitDeg":0.404,"moonDistanceKm":405393.5033,"borderline":false},"degraded":false,"notChecked":["where an eclipse is visible: this says an eclipse occurs somewhere (solar) or is geometrically possible for the Moon (lunar), not that you can see it","exact eclipse magnitude, duration, path of totality or gamma: the screen uses the Moon's ecliptic latitude at the new/full moon, so results within 0.05 degrees of a limit are flagged BORDERLINE and ne…","…2 more"],"source":"Meeus, Astronomical Algorithms ch. 47, 25, 54 (eclipse limits) with our own shadow geometry; computed locally","asOf":"2026-10-21T01:01:41.188Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0200"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/eclipse-check"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/eclipse-check"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/eclipse-check"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/eclipse-check"}}]}}},"/equation-of-time":{"get":{"operationId":"equation_of_time","summary":"Equation of time in minutes for a date (sundial minus clock), and the clock time of solar noon at a longitude.","description":"Equation of time in minutes for a date (sundial minus clock), and the clock time of solar noon at a longitude.","tags":["equation-of-time","solar-noon","sundial","astronomy"],"parameters":[{"name":"date","in":"query","required":true,"description":"YYYY-MM-DD (UTC), 1900 to 2100","schema":{"type":"string"}},{"name":"time","in":"query","required":false,"description":"UTC HH:MM, default 12:00","schema":{"type":"string"}},{"name":"lon","in":"query","required":false,"description":"Longitude east positive, to get the UTC time of solar noon there","schema":{"type":"number"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"datetimeUtc":{"type":["null","string"]},"equationOfTimeMinutes":{"type":["null","number"]},"equationOfTimeSeconds":{"type":["null","number"]},"sundialAheadOfClock":{"type":["boolean","null"]},"longitude":{"type":["null","number"]},"solarNoonUtc":{"type":["null","string"]},"accuracy":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"COMPUTED","summary":"On 2026-11-03 the equation of time is +16 min 27 s: the sundial runs ahead of the clock. Solar noon at longitude -74.006 is 16:40 UTC.","reasons":["Equation of time = apparent solar time minus mean solar time. Positive means the true Sun crosses the meridian before mean noon, so the sundial is ahead of a clock set to mean solar time.","It swings between about -14 min 15 s (mid February) and +16 min 25 s (early November), crosses zero near 15 April, 13 June, 1 September and 25 December.","…1 more"],"datetimeUtc":"2026-11-03T12:00:00Z","equationOfTimeMinutes":16.442,"equationOfTimeSeconds":986.5,"sundialAheadOfClock":true,"longitude":-74.006,"solarNoonUtc":"2026-11-03T16:39:35Z","accuracy":"a few seconds or better","degraded":false,"notChecked":["time zone rules and daylight saving (solar noon is given in UTC; add your zone offset yourself)","accuracy: about 0.1 second to a few seconds of time in 1900 to 2100 with this low-order formulation, far below what a sundial can show","…1 more"],"source":"Meeus, Astronomical Algorithms ch. 28 (equation of time) with ch. 25 and ch. 22; computed locally","asOf":"2026-10-21T01:01:41.439Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0200"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/equation-of-time"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/equation-of-time"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/equation-of-time"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/equation-of-time"}}]}}},"/moon-position":{"get":{"operationId":"moon_position","summary":"Moon azimuth and altitude for a lat/lon and UTC moment, plus distance in km, illuminated fraction, phase and parallax.","description":"Moon azimuth and altitude for a lat/lon and UTC moment, plus distance in km, illuminated fraction, phase and parallax.","tags":["moon","astronomy","azimuth","altitude","lunar"],"parameters":[{"name":"lat","in":"query","required":true,"description":"Latitude, -90 to 90 (north positive)","schema":{"type":"number"}},{"name":"lon","in":"query","required":true,"description":"Longitude, -180 to 180 (east positive)","schema":{"type":"number"}},{"name":"datetime","in":"query","required":false,"description":"ISO 8601 with zone, e.g. 2026-10-20T01:00:00Z. Default now","schema":{"type":"string"}},{"name":"date","in":"query","required":false,"description":"YYYY-MM-DD (UTC) if datetime is not given","schema":{"type":"string"}},{"name":"time","in":"query","required":false,"description":"UTC HH:MM with date, default 12:00","schema":{"type":"string"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"datetimeUtc":{"type":["null","string"]},"lat":{"type":["null","number"]},"lon":{"type":["null","number"]},"azimuthDeg":{"type":["null","number"]},"compass":{"type":["null","string"]},"altitudeGeometricDeg":{"type":["null","number"]},"altitudeApparentDeg":{"type":["null","number"]},"altitudeGeocentricDeg":{"type":["null","number"]},"refractionDeg":{"type":["null","number"]},"distanceKm":{"type":["null","number"]},"horizontalParallaxDeg":{"type":["null","number"]},"angularDiameterDeg":{"type":["null","number"]},"illuminatedFraction":{"type":["null","number"]},"phaseAngleDeg":{"type":["null","number"]},"elongationDeg":{"type":["null","number"]},"waxing":{"type":["boolean","null"]},"phase":{"type":["null","string"]},"eclipticLongitudeDeg":{"type":["null","number"]},"eclipticLatitudeDeg":{"type":["null","number"]},"rightAscensionDeg":{"type":["null","number"]},"rightAscension":{"type":["null","string"]},"declinationDeg":{"type":["null","number"]},"accuracy":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"MOON_UP","summary":"At 2026-10-20T20:00:00Z the Moon is 22.6 degrees above the horizon, azimuth 185.5 degrees (S), 395,305 km away, 70 percent lit (Waxing Gibbous).","reasons":["Altitude and azimuth are TOPOCENTRIC: the Moon's parallax (up to about 1 degree) is applied for an observer at sea level. altitudeGeocentricDeg is the value as seen from Earth's centre.","Illuminated fraction is (1 + cos i) / 2 where i is the Sun-Moon-Earth phase angle (Meeus ch. 48).","…1 more"],"datetimeUtc":"2026-10-20T20:00:00Z","lat":51.5074,"lon":-0.1278,"azimuthDeg":185.471,"compass":"S","altitudeGeometricDeg":22.555,"altitudeApparentDeg":22.596,"altitudeGeocentricDeg":23.406,"refractionDeg":0.04,"distanceKm":395305,"horizontalParallaxDeg":0.9245,"angularDiameterDeg":0.5036,"illuminatedFraction":0.7041,"phaseAngleDeg":65.91,"elongationDeg":113.95,"waxing":true,"phase":"Waxing Gibbous","eclipticLongitudeDeg":321.3932,"eclipticLatitudeDeg":-0.593,"rightAscensionDeg":323.9703,"rightAscension":"21h 35m 52.9s","declinationDeg":-14.932,"accuracy":"about 0.01 degree in position","degraded":false,"notChecked":["libration, the tilt of the lunar disc as seen from the observer (parallactic angle) and the Moon's apparent diameter on the sky","terrain and building horizons","…4 more"],"source":"Meeus, Astronomical Algorithms ch. 47 (Moon, full series), ch. 40 (parallax), ch. 48 (illumination), ch. 16; computed locally","asOf":"2026-10-21T01:01:41.710Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0200"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/moon-position"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/moon-position"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/moon-position"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/moon-position"}}]}}},"/planet-positions":{"get":{"operationId":"planet_positions","summary":"Geocentric ecliptic longitude/latitude, RA/Dec, distance and Sun elongation for Mercury to Neptune; arcminute accuracy.","description":"Geocentric ecliptic longitude/latitude, RA/Dec, distance and Sun elongation for Mercury to Neptune; arcminute accuracy.","tags":["planets","astronomy","ephemeris","right-ascension","ecliptic"],"parameters":[{"name":"datetime","in":"query","required":false,"description":"ISO 8601 with zone, e.g. 2026-10-20T00:00:00Z. Default now","schema":{"type":"string"}},{"name":"date","in":"query","required":false,"description":"YYYY-MM-DD (UTC) if datetime is not given","schema":{"type":"string"}},{"name":"time","in":"query","required":false,"description":"UTC HH:MM with date, default 12:00","schema":{"type":"string"}},{"name":"planets","in":"query","required":false,"description":"Comma list from mercury,venus,mars,jupiter,saturn,uranus,neptune; default all","schema":{"type":"string"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"datetimeUtc":{"type":["null","string"]},"equinox":{"type":["null","string"]},"method":{"type":["null","string"]},"accuracyArcminutes":{"type":["null","string"]},"planets":{"type":["array","null"],"items":{"type":"object","properties":{"planet":{"type":["null","string"]},"eclipticLongitudeDeg":{"type":["null","number"]},"eclipticLatitudeDeg":{"type":["null","number"]},"rightAscensionDeg":{"type":["null","number"]},"rightAscension":{"type":["null","string"]},"declinationDeg":{"type":["null","number"]},"distanceAu":{"type":["null","number"]},"distanceFromSunAu":{"type":["null","number"]},"elongationFromSunDeg":{"type":["null","number"]},"sunSide":{"type":["null","string"]},"lightTimeMinutes":{"type":["null","number"]}}}},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"COMPUTED","summary":"4 planets for 2026-10-20T00:00:00Z: Venus ecliptic longitude 213.231 deg, elongation 9.69 deg E; Mars ecliptic longitude 132.364 deg, elongation 74.26 deg W; Jupiter ecliptic longitude 142.708 deg, el…","reasons":["Positions are geocentric, referred to the mean equinox of date (not J2000). Right ascension is shown in degrees and as hours/minutes/seconds.","Accuracy is arcminutes, not arcseconds: see notChecked. Elongation is the angular distance from the Sun; EAST of the Sun means visible after sunset."],"datetimeUtc":"2026-10-20T00:00:00Z","equinox":"mean of date","method":"Keplerian elements with Jupiter/Saturn/Uranus perturbations","accuracyArcminutes":"about 1 to 2, up to about 3 for some dates","planets":[{"planet":"Venus","eclipticLongitudeDeg":213.231,"eclipticLatitudeDeg":-7.106,"rightAscensionDeg":208.45,"rightAscension":"13h 53m 48.0s","declinationDeg":-19.255,"distanceAu":0.2766,"distanceFromSunAu":0.7248,"elongationFromSunDeg":9.69,"sunSide":"EAST (evening sky)","lightTimeMinutes":2.3},{"planet":"Mars","eclipticLongitudeDeg":132.364,"eclipticLatitudeDeg":1.36,"rightAscensionDeg":135.229,"rightAscension":"9h 00m 54.9s","declinationDeg":18.395,"distanceAu":1.5272,"distanceFromSunAu":1.5808,"elongationFromSunDeg":74.26,"sunSide":"WEST (morning sky)","lightTimeMinutes":12.7}],"degraded":false,"notChecked":["arcsecond accuracy: this is a LOW-PRECISION method, measured here at under about 2 arcminutes for 1950 to 2075 against the Astronomy Engine ephemeris (Saturn and Uranus a little worse), so it is fine …","aberration, nutation and light-time (a few tens of arcseconds)","…4 more"],"source":"Keplerian mean elements with perturbation terms (Paul Schlyter, 'How to compute planetary positions'); Meeus ch. 13; computed locally","asOf":"2026-10-21T01:01:41.967Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0200"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-positions"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-positions"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-positions"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-positions"}}]}}},"/planet-visibility":{"get":{"operationId":"planet_visibility","summary":"Which planets are above the horizon an hour after sunset for a lat/lon and date: altitude, azimuth, elongation, set time.","description":"Which planets are above the horizon an hour after sunset for a lat/lon and date: altitude, azimuth, elongation, set time.","tags":["planets","visibility","evening-sky","astronomy","stargazing"],"parameters":[{"name":"lat","in":"query","required":true,"description":"Latitude, -90 to 90 (north positive)","schema":{"type":"number"}},{"name":"lon","in":"query","required":true,"description":"Longitude, -180 to 180 (east positive)","schema":{"type":"number"}},{"name":"date","in":"query","required":true,"description":"Local calendar date YYYY-MM-DD, 1900 to 2100","schema":{"type":"string"}},{"name":"utc_offset_hours","in":"query","required":false,"description":"Local UTC offset in hours, -12 to 14, default 0","schema":{"type":"number"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"date":{"type":["null","string"]},"lat":{"type":["null","number"]},"lon":{"type":["null","number"]},"utcOffsetHours":{"type":["null","number"]},"sunset":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"checkTime":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"sunAltitudeAtCheckDeg":{"type":["null","number"]},"planets":{"type":["array","null"],"items":{"type":"object","properties":{"planet":{"type":["null","string"]},"status":{"type":["null","string"]},"nakedEye":{"type":["boolean","null"]},"altitudeDeg":{"type":["null","number"]},"azimuthDeg":{"type":["null","number"]},"compass":{"type":["null","string"]},"elongationFromSunDeg":{"type":["null","number"]},"sunSide":{"type":["null","string"]},"sets":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"minutesAboveHorizonAfterCheck":{"type":["null","number"]}}}},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"PLANETS_WELL_PLACED","summary":"2026-10-20 at 19:08 local (one hour after sunset at 18:08): naked-eye planets well placed: Saturn (17.6 deg ESE); telescope or binoculars only: Neptune.","reasons":["The check time is one hour after sunset (2026-10-20T23:08:13Z), when the Sun is -12.1 degrees below the horizon.","WELL_PLACED: above 10 degrees and more than 15 degrees from the Sun. LOW_OR_NEAR_SUN: above the horizon but under 10 degrees up or within 15 degrees of the Sun. BELOW_HORIZON: not up.","…1 more"],"date":"2026-10-20","lat":40.7128,"lon":-74.006,"utcOffsetHours":-4,"sunset":{"utc":"2026-10-20T22:08:13Z","local":"18:08"},"checkTime":{"utc":"2026-10-20T23:08:13Z","local":"19:08"},"sunAltitudeAtCheckDeg":-12.1,"planets":[{"planet":"Mercury","status":"BELOW_HORIZON","nakedEye":true,"altitudeDeg":-3.2,"azimuthDeg":245,"compass":"WSW","elongationFromSunDeg":22.9,"sunSide":"EAST","sets":null,"minutesAboveHorizonAfterCheck":0},{"planet":"Venus","status":"BELOW_HORIZON","nakedEye":true,"altitudeDeg":-15.6,"azimuthDeg":258.2,"compass":"WSW","elongationFromSunDeg":8.6,"sunSide":"EAST","sets":null,"minutesAboveHorizonAfterCheck":0}],"degraded":false,"notChecked":["apparent brightness (magnitude), phase and size: a planet marked above the horizon may still be too faint or washed out by twilight","weather, light pollution and terrain/building horizons","…3 more"],"source":"Meeus ch. 25, 12, 13 (Sun, horizon coordinates) and Schlyter Keplerian planet positions (arcminute accuracy); computed locally","asOf":"2026-10-21T01:01:42.234Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0300"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-visibility"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-visibility"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-visibility"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/planet-visibility"}}]}}},"/rise-set-moon":{"get":{"operationId":"rise_set_moon","summary":"Moonrise, moonset and transit for a lat/lon and local date, with azimuths and illumination; handles days with no rise or set.","description":"Moonrise, moonset and transit for a lat/lon and local date, with azimuths and illumination; handles days with no rise or set.","tags":["moonrise","moonset","moon","astronomy","lunar"],"parameters":[{"name":"lat","in":"query","required":true,"description":"Latitude, -90 to 90 (north positive)","schema":{"type":"number"}},{"name":"lon","in":"query","required":true,"description":"Longitude, -180 to 180 (east positive)","schema":{"type":"number"}},{"name":"date","in":"query","required":true,"description":"Local calendar date YYYY-MM-DD, 1900 to 2100","schema":{"type":"string"}},{"name":"utc_offset_hours","in":"query","required":false,"description":"Local UTC offset in hours, -12 to 14, default 0 (the date is then a UTC day)","schema":{"type":"number"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"date":{"type":["null","string"]},"lat":{"type":["null","number"]},"lon":{"type":["null","number"]},"utcOffsetHours":{"type":["null","number"]},"moonrise":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]},"azimuthDeg":{"type":["null","number"]},"compass":{"type":["null","string"]},"illuminatedFraction":{"type":["null","number"]}}},"moonset":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]},"azimuthDeg":{"type":["null","number"]},"compass":{"type":["null","string"]},"illuminatedFraction":{"type":["null","number"]}}},"upperTransit":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]},"altitudeDeg":{"type":["null","number"]}}},"phaseAtTransit":{"type":["null","string"]},"illuminatedFractionAtTransit":{"type":["null","number"]},"riseSetAltitudeUsedDeg":{"type":["null","number"]},"accuracy":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"RISES_AND_SETS","summary":"2026-10-20: moonrise 15:55, moonset 00:19 (UTC+1); 70 percent lit (Waxing Gibbous).","reasons":["Rise and set are when the Moon's centre, seen from Earth's centre, passes 0.7275 * horizontal parallax - 34 arcminutes (about +0.13 degrees); this equals the upper limb touching the real horizon for a…","Moonrise and moonset can fall on different local dates, so a date may show only one of them."],"date":"2026-10-20","lat":51.5074,"lon":-0.1278,"utcOffsetHours":1,"moonrise":{"utc":"2026-10-20T14:55:14Z","local":"15:55","azimuthDeg":116.4,"compass":"ESE","illuminatedFraction":0.685},"moonset":{"utc":"2026-10-19T23:18:30Z","local":"00:19","azimuthDeg":238.4,"compass":"WSW","illuminatedFraction":0.624},"upperTransit":{"utc":"2026-10-20T19:38:35Z","local":"20:39","altitudeDeg":22.6},"phaseAtTransit":"Waxing Gibbous","illuminatedFractionAtTransit":0.703,"riseSetAltitudeUsedDeg":0.103,"accuracy":"about 1 to 2 minutes at mid latitudes","degraded":false,"notChecked":["terrain and building horizons","weather and unusual refraction","…3 more"],"source":"Meeus, Astronomical Algorithms ch. 47, 40, 15; computed locally by scanning the Moon's altitude curve","asOf":"2026-10-21T01:01:42.500Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0200"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-moon"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-moon"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-moon"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-moon"}}]}}},"/rise-set-sun":{"get":{"operationId":"rise_set_sun","summary":"Sunrise, sunset, solar noon, three twilights, golden and blue hour for a lat/lon and date; handles polar day and night.","description":"Sunrise, sunset, solar noon, three twilights, golden and blue hour for a lat/lon and date; handles polar day and night.","tags":["sunrise","sunset","twilight","golden-hour","astronomy"],"parameters":[{"name":"lat","in":"query","required":true,"description":"Latitude, -90 to 90 (north positive)","schema":{"type":"number"}},{"name":"lon","in":"query","required":true,"description":"Longitude, -180 to 180 (east positive)","schema":{"type":"number"}},{"name":"date","in":"query","required":true,"description":"Local calendar date YYYY-MM-DD, 1900 to 2100","schema":{"type":"string"}},{"name":"utc_offset_hours","in":"query","required":false,"description":"Local UTC offset in hours, -12 to 14, default 0 (the date is then a UTC day)","schema":{"type":"number"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"date":{"type":["null","string"]},"lat":{"type":["null","number"]},"lon":{"type":["null","number"]},"utcOffsetHours":{"type":["null","number"]},"localDayStartUtc":{"type":["null","string"]},"sunrise":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"sunset":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"solarNoon":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"dayLengthMinutes":{"type":["null","number"]},"civilDawn":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"civilDusk":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"nauticalDawn":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"nauticalDusk":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"astronomicalDawn":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"astronomicalDusk":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"goldenHourMorning":{"type":["null","object"],"properties":{"start":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"end":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}}}},"goldenHourEvening":{"type":["null","object"],"properties":{"start":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"end":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}}}},"blueHourMorning":{"type":["null","object"],"properties":{"start":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"end":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}}}},"blueHourEvening":{"type":["null","object"],"properties":{"start":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}},"end":{"type":["null","object"],"properties":{"utc":{"type":["null","string"]},"local":{"type":["null","string"]}}}}},"maxAltitudeDeg":{"type":["null","number"]},"sunAltitudeAtLocalMidnightDeg":{"type":["null","number"]},"accuracy":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"NORMAL_DAY","summary":"2026-06-21: sunrise 05:25, sunset 20:31 (UTC-4), day length 15 h 6 min.","reasons":["Sunrise and sunset use the Sun's centre at -0.833 degrees (refraction plus the Sun's radius). Civil, nautical and astronomical twilight begin or end when the centre is 6, 12 and 18 degrees below the h…","Golden hour here means the Sun between -4 and +6 degrees altitude; blue hour between -8 and -4 degrees. These are photographers' conventions, not official definitions."],"date":"2026-06-21","lat":40.7128,"lon":-74.006,"utcOffsetHours":-4,"localDayStartUtc":"2026-06-21T04:00:00Z","sunrise":{"utc":"2026-06-21T09:25:01Z","local":"05:25"},"sunset":{"utc":"2026-06-22T00:30:46Z","local":"20:31"},"solarNoon":{"utc":"2026-06-21T16:57:54Z","local":"12:58"},"dayLengthMinutes":905.7,"civilDawn":{"utc":"2026-06-21T08:51:36Z","local":"04:52"},"civilDusk":{"utc":"2026-06-22T01:04:12Z","local":"21:04"},"nauticalDawn":{"utc":"2026-06-21T08:08:56Z","local":"04:09"},"nauticalDusk":{"utc":"2026-06-22T01:46:52Z","local":"21:47"},"astronomicalDawn":{"utc":"2026-06-21T07:18:31Z","local":"03:19"},"astronomicalDusk":{"utc":"2026-06-22T02:37:17Z","local":"22:37"},"goldenHourMorning":{"start":{"utc":"2026-06-21T09:04:49Z","local":"05:05"},"end":{"utc":"2026-06-21T10:06:21Z","local":"06:06"}},"goldenHourEvening":{"start":{"utc":"2026-06-21T23:49:27Z","local":"19:49"},"end":{"utc":"2026-06-22T00:50:59Z","local":"20:51"}},"blueHourMorning":{"start":{"utc":"2026-06-21T08:37:56Z","local":"04:38"},"end":{"utc":"2026-06-21T09:04:49Z","local":"05:05"}},"blueHourEvening":{"start":{"utc":"2026-06-22T00:50:59Z","local":"20:51"},"end":{"utc":"2026-06-22T01:17:51Z","local":"21:18"}},"maxAltitudeDeg":72.72,"sunAltitudeAtLocalMidnightDeg":-24.46,"accuracy":"about 1 minute at mid latitudes","degraded":false,"notChecked":["terrain and building horizons (hills and buildings shorten the usable day)","weather and unusual refraction (standard -0.833 degree rise/set altitude is used: 34 arcminutes refraction plus the Sun's 16 arcminute radius)","…3 more"],"source":"Meeus, Astronomical Algorithms ch. 25, 12, 13, 15; computed locally by scanning the Sun's altitude curve","asOf":"2026-10-21T01:01:42.756Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0200"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-sun"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-sun"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-sun"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/rise-set-sun"}}]}}},"/sun-position":{"get":{"operationId":"sun_position","summary":"Sun azimuth and altitude for a lat/lon and UTC moment, with refraction-corrected altitude, RA/Dec, distance and twilight phase.","description":"Sun azimuth and altitude for a lat/lon and UTC moment, with refraction-corrected altitude, RA/Dec, distance and twilight phase.","tags":["sun","astronomy","azimuth","altitude","solar"],"parameters":[{"name":"lat","in":"query","required":true,"description":"Latitude, -90 to 90 (north positive)","schema":{"type":"number"}},{"name":"lon","in":"query","required":true,"description":"Longitude, -180 to 180 (east positive)","schema":{"type":"number"}},{"name":"datetime","in":"query","required":false,"description":"ISO 8601 with zone, e.g. 2026-06-21T18:30:00Z. Default now","schema":{"type":"string"}},{"name":"date","in":"query","required":false,"description":"YYYY-MM-DD (UTC) if datetime is not given","schema":{"type":"string"}},{"name":"time","in":"query","required":false,"description":"UTC HH:MM with date, default 12:00","schema":{"type":"string"}}],"responses":{"200":{"description":"The answer.","content":{"application/json":{"schema":{"type":"object","properties":{"verdict":{"type":["null","string"]},"summary":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"datetimeUtc":{"type":["null","string"]},"lat":{"type":["null","number"]},"lon":{"type":["null","number"]},"azimuthDeg":{"type":["null","number"]},"compass":{"type":["null","string"]},"altitudeGeometricDeg":{"type":["null","number"]},"altitudeApparentDeg":{"type":["null","number"]},"refractionDeg":{"type":["null","number"]},"hourAngleDeg":{"type":["null","number"]},"rightAscensionDeg":{"type":["null","number"]},"rightAscension":{"type":["null","string"]},"declinationDeg":{"type":["null","number"]},"eclipticLongitudeDeg":{"type":["null","number"]},"distanceAu":{"type":["null","number"]},"distanceKm":{"type":["null","number"]},"isAboveHorizon":{"type":["boolean","null"]},"shadowLengthPerUnitHeight":{"type":["null","number"]},"deltaTSeconds":{"type":["null","number"]},"accuracy":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"source":{"type":["null","string"]},"asOf":{"type":["null","string"]},"disclaimer":{"type":["null","string"]}}},"example":{"verdict":"DAY","summary":"At 2026-06-21T16:00:00Z the Sun is 68.89 degrees above the horizon, azimuth 140.5 degrees (SE). Phase: day.","reasons":["Azimuth is degrees clockwise from true north. Altitude is the Sun's centre.","altitudeGeometricDeg ignores the atmosphere; altitudeApparentDeg adds standard refraction (Saemundsson formula), about 0.5 degrees at the horizon.","…1 more"],"datetimeUtc":"2026-06-21T16:00:00Z","lat":40.7128,"lon":-74.006,"azimuthDeg":140.48,"compass":"SE","altitudeGeometricDeg":68.879,"altitudeApparentDeg":68.885,"refractionDeg":0.007,"hourAngleDeg":-14.473,"rightAscensionDeg":90.3327,"rightAscension":"6h 01m 19.9s","declinationDeg":23.4378,"eclipticLongitudeDeg":90.3053,"distanceAu":1.016251,"distanceKm":152028918,"isAboveHorizon":true,"shadowLengthPerUnitHeight":0.386,"deltaTSeconds":75.4,"accuracy":"about 0.01 degree","degraded":false,"notChecked":["terrain and building horizons","weather: refraction assumes a standard atmosphere (1010 mb, 10 C) and is unreliable within about 1 degree of the horizon","…2 more"],"source":"Meeus, Astronomical Algorithms ch. 25 (Sun, 0.01 degree), ch. 12-13, ch. 16; computed locally","asOf":"2026-10-21T01:01:43.016Z","disclaimer":"Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting."}}}},"400":{"description":"A parameter was missing or out of range."},"402":{"description":"Payment Required"},"502":{"description":"The upstream source failed or timed out."}},"x-payment-info":{"price":{"mode":"fixed","currency":"USD","amount":"0.0200"},"protocols":[{"x402":{"network":"eip155:8453","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/sun-position"}},{"x402":{"network":"solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/sun-position"}},{"x402":{"network":"eip155:137","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/sun-position"}},{"x402":{"network":"eip155:42161","scheme":"exact","currency":"USDC","endpoint":"https://sky-calc.x402tookit.com/sun-position"}}]}}}}}