CycleCalcs · Example Payload
Cyclecalcs V2 Sun Example
AstronomySpaceScienceEphemerisSunMoonPlanetsEclipsesTimeCalendarGeolocationMCPAgent-native
Cyclecalcs V2 Sun Example is an example object payload from CycleCalcs, with 9 top-level fields. It illustrates the shape of data this provider's APIs accept or return.
Top-level fields
endpointcomputed_atquerydatawarningslinksmetaattributiondocs
Example Payload
{
"endpoint": "/v2/sun",
"computed_at": "2026-08-01T00:00:00.000Z",
"query": {
"at": "2026-07-26T23:00:00.000Z",
"mode": "instant",
"resolved_from": "at",
"is_now": false,
"latitude": 51.4778,
"longitude": -0.0015,
"elevation_m": 0,
"tz": "Europe/London",
"utc_offset_seconds": 3600,
"utc_offset_iso": "+01:00",
"is_dst": true,
"timezone_source": "parameter",
"day_anchor": "civil",
"time_format": "iso",
"format": "json",
"shape": "nested",
"precision": 6,
"pretty": 1,
"verbosity": "full",
"depressions": [
17,
18
],
"ignored": []
},
"data": {
"window": {
"start": "2026-07-27T00:00:00.000+01:00",
"end": "2026-07-28T00:00:00.000+01:00",
"anchor": "civil",
"length_minutes": 1440,
"local_date": "2026-07-27"
},
"rise_set": {
"status": "normal",
"status_label": "Rises and sets",
"special": null,
"events": [
{
"kind": "lower_transit",
"instant": "2026-07-27T01:06:33.985+01:00",
"azimuth_deg": 359.999871,
"altitude_deg": -18.760119
},
{
"kind": "rise",
"instant": "2026-07-27T05:16:24.076+01:00",
"azimuth_deg": 56.865535,
"altitude_deg": -0.83332
},
{
"kind": "upper_transit",
"instant": "2026-07-27T13:06:33.658+01:00",
"azimuth_deg": 179.999987,
"altitude_deg": 57.668914
},
{
"kind": "set",
"instant": "2026-07-27T20:55:46.285+01:00",
"azimuth_deg": 302.865673,
"altitude_deg": -0.833301
}
],
"rise": [
"2026-07-27T05:16:24.076+01:00"
],
"set": [
"2026-07-27T20:55:46.285+01:00"
],
"transit": [
"2026-07-27T13:06:33.658+01:00"
],
"above_horizon_minutes": 939.4
},
"solar_noon": "2026-07-27T13:06:33.658+01:00",
"solar_noon_altitude_deg": 57.668914,
"solar_noon_altitude_refracted_deg": 57.668914,
"solar_noon_altitude_unrefracted_deg": 57.658218,
"solar_noon_azimuth_deg": 179.999987,
"solar_midnight": "2026-07-27T01:06:33.985+01:00",
"solar_midnight_altitude_deg": -18.760119,
"solar_midnight_altitude_refracted_deg": -18.760119,
"solar_midnight_altitude_unrefracted_deg": -19.273941,
"day_length": "15h 39m",
"day_length_minutes": 939.4,
"day_length_seconds": 56362,
"day_length_change_from_yesterday_seconds": -173,
"twilight": {
"civil": {
"dawn": "2026-07-27T04:34:35.829+01:00",
"dusk": "2026-07-27T21:37:19.111+01:00",
"altitude_deg": -6,
"definition": "The band runs from -6 to -0.8333 degrees of unrefracted solar altitude. dawn and dusk are the instants the Sun crosses -6 deg, and the two duration fields are the time the Sun spends inside this band, not the time until sunrise or since sunset.",
"duration_morning_minutes": 41.8,
"duration_evening_minutes": 41.5
},
"nautical": {
"dawn": "2026-07-27T03:37:13.834+01:00",
"dusk": "2026-07-27T22:34:05.867+01:00",
"altitude_deg": -12,
"definition": "The band runs from -12 to -6 degrees of unrefracted solar altitude. dawn and dusk are the instants the Sun crosses -12 deg, and the two duration fields are the time the Sun spends inside this band, not the time until sunrise or since sunset.",
"duration_morning_minutes": 57.4,
"duration_evening_minutes": 56.8
},
"astronomical": {
"dawn": "2026-07-27T02:08:20.099+01:00",
"dusk": "2026-07-28T00:00:00.615+01:00",
"altitude_deg": -18,
"definition": "The band runs from -18 to -12 degrees of unrefracted solar altitude. dawn and dusk are the instants the Sun crosses -18 deg, and the two duration fields are the time the Sun spends inside this band, not the time until sunrise or since sunset.",
"duration_morning_minutes": 88.9,
"duration_evening_minutes": 85.9
}
},
"custom": [
{
"depression_deg": 17,
"dawn": "2026-07-27T02:29:19.747+01:00",
"dusk": "2026-07-27T23:40:16.028+01:00"
},
{
"depression_deg": 18,
"dawn": "2026-07-27T02:08:20.099+01:00",
"dusk": "2026-07-28T00:00:00.615+01:00"
}
],
"golden_hour": {
"morning": {
"begin": "2026-07-27T04:51:20.851+01:00",
"end": "2026-07-27T06:06:20.750+01:00"
},
"evening": {
"begin": "2026-07-27T20:06:02.115+01:00",
"end": "2026-07-27T21:20:41.036+01:00"
},
"definition": "Sun centre from -4 degrees to +6 degrees."
},
"blue_hour": {
"morning": {
"begin": "2026-07-27T04:34:35.829+01:00",
"end": "2026-07-27T04:51:20.851+01:00"
},
"evening": {
"begin": "2026-07-27T21:20:41.036+01:00",
"end": "2026-07-27T21:37:19.111+01:00"
},
"definition": "Sun centre from -6 degrees to -4 degrees."
},
"night_begins": "2026-07-28T00:00:00.615+01:00",
"night_ends": "2026-07-28T02:13:34.005+01:00",
"dark_minutes": 133.6,
"position_now": {
"instant": "2026-07-27T00:00:00.000+01:00",
"basis": "requested_instant",
"basis_definition": "Evaluated at the instant you asked for.",
"azimuth_deg": 343.506415,
"compass": "NNW",
"altitude_refracted_deg": -17.250728,
"altitude_unrefracted_deg": -17.775436,
"refraction_deg": 0.524708,
"declination_of_date_deg": 19.258682,
"hour_angle_hours": 10.890574,
"shadow_length_multiplier": null,
"is_up": false
},
"tropical_sign": {
"name": "Leo",
"code": "leo",
"sign_index": 4,
"degree_in_sign": 3.970404,
"degree_in_sign_whole": 3
},
"constellation": {
"name": "Cancer",
"abbreviation": "Cnc"
},
"summary": "The Sun rises at 05:16 and sets at 20:55 local time, giving 15 hours 39 minutes of daylight."
},
"warnings": [],
"links": {
"self": "https://www.cyclecalcs.com/v2/sun?at=2026-07-27&depressions=17%2C18&lat=51.4778&lon=-0.0015&tz=Europe%2FLondon",
"docs": "https://www.cyclecalcs.com/api/reference.html#sun",
"spec": "https://www.cyclecalcs.com/v2/openapi.json",
"page": "https://www.cyclecalcs.com/sunrise-sunset-calculator.html",
"explain": "https://www.cyclecalcs.com/learn/seasons.html"
},
"meta": {
"api_version": "2",
"contract_version": "2.0.0",
"engine": {
"name": "Astronomy Engine",
"license": "MIT",
"author": "Don Cross",
"version": "2.1.19",
"version_source": "upstream_sha256_match",
"sha256": "068f1445ed0c636c94818fe6d20d7d125120e605e0bab9fc4675c3d531be5ad7",
"vendored": true,
"credit": "astronomy-engine (MIT, Copyright (c) 2019-2023 Don Cross)"
},
"tzdb": "2026b",
"rights": "unrestricted",
"attribution": {
"required": false,
"text": "Computed by CycleCalcs (cyclecalcs.com) with the MIT-licensed Astronomy Engine. Positional astronomy only.",
"sources": []
},
"notice_url": "https://www.cyclecalcs.com/methodology.html#data-sources",
"cache": {
"class": "fixed_instant",
"deterministic": true
},
"accuracy": {
"statement": "Positions are arcminute class for the Sun, Moon and planets across 1700 to 2200, degrading toward the ends of that window.",
"residuals_url": "https://www.cyclecalcs.com/api/accuracy.html"
},
"time": {
"scale_of_input": "UTC",
"ut1_source": "assumed equal to UTC; no IERS bulletin is loaded, so UT1 minus UTC may differ by up to 0.9 s",
"delta_t_seconds": 75.4,
"delta_t_model": "Espenak and Meeus"
},
"not_computed": [
{
"name": "constellation.genitive",
"reason": "Needs the reduced constellation index; the generator has not run yet."
}
],
"horizon": {
"sunrise_sunset_altitude_deg": -0.8333,
"sunrise_sunset_definition": "centre of the Sun 50 arcminutes below the true horizon, being about 16 arcminutes of solar semidiameter plus about 34 arcminutes of horizon refraction",
"civil_twilight_altitude_deg": -6,
"nautical_twilight_altitude_deg": -12,
"astronomical_twilight_altitude_deg": -18,
"horizon_dip_modelled": false,
"horizon_dip_arcmin_if_modelled": 0,
"horizon_dip_note": "Observer elevation raises the observer on a locally flat plateau. Dip of the sea horizon is not modelled. The value you are forgoing is 1.753 times the square root of the elevation in metres, in arcminutes."
},
"refraction": {
"model": "Saemundsson (Astronomy Engine normal mode)",
"verified": true,
"assumed_temperature_c": null,
"assumed_pressure_mbar": null,
"applied_below_horizon_down_to_deg": -1
},
"method": {
"solar_noon": "A true upper transit from the engine hour-angle search, not the midpoint of sunrise and sunset that /v1 returns. The two can differ by tens of seconds, most where the equation of time is changing fastest.",
"ecliptic_source": "Ecliptic(GeoVector(Sun)), used consistently across v2."
},
"budget": {
"engine_calls": 58
}
},
"attribution": "Computed by CycleCalcs (cyclecalcs.com) with the MIT-licensed Astronomy Engine. Positional astronomy only.",
"docs": "https://www.cyclecalcs.com/api/reference.html#sun"
}