Equation of time API

Returns the equation of time (minutes/seconds) — the difference between apparent and mean solar time — and the solar declination for a given UTC instant, via the NOAA solar approximation. Answers 'How far ahead is a sundial today?', 'Equation of time for this date?'.

Price$0.06per request

MethodPOST

Route/v1/space/equation-of-time

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

spaceastronomyequation-of-timesolar-timesundialdeclinationpositional-astronomyanalemma

API URLhttps://x402.hexl.dev/v1/space/equation-of-time

Integration docs

Example request

{
  "date": "2024-11-03T12:00:00Z"
}

Example response

{
  "date": "2024-11-03T12:00:00.000Z",
  "julianDate": 2460618,
  "eotMinutes": 16.4435,
  "eotSeconds": 986.61,
  "sunDeclinationDeg": -15.298514,
  "interpretation": "Sundials run ahead of clock time by 16.44 min."
}

Input schema

{
  "type": "object",
  "required": [
    "date"
  ],
  "properties": {
    "date": {
      "type": "string",
      "description": "ISO 8601 date/time (UTC)",
      "examples": [
        "2024-11-03T12:00:00Z"
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}