# fittings Solar Twilight Windows

> fittings Solar Twilight Windows is a paid API for AI agents from fittings.sh, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).

Returns civil, nautical, and astronomical twilight boundaries plus golden and blue hour windows for a given date and coordinate, in UTC.

## Facts

- Endpoint: GET https://fittings.sh/v1/solar/twilight-windows
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fittings-solar-twilight-windows-c137bfa0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KLssQGYiFDdjpqj6VG_Rq

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fittings-solar-twilight-windows-c137bfa0
```

Example prompt: What are the civil, nautical, and astronomical twilight times plus golden hour and blue hour windows for Reykjavik (64.1355° N, 21.8954° W) on July 15, 2025?

## When to prefer this

Choose this endpoint when you need precise UTC twilight boundary times (civil, nautical, astronomical) and golden/blue hour windows for any geographic coordinate and date. It's ideal for photography planning, astronomical observation scheduling, nautical departure planning, or drone flight window calculation. Prefer it over generic solar APIs when you need all twilight categories plus golden and blue hour in a single call.

## Known failure modes

- Missing required query parameters (date, lat, or lon) returns a validation error
- Latitude out of range (-90 to 90) or longitude out of range (-180 to 180) returns an error
- Malformed date string (not YYYY-MM-DD) returns a parsing error
- Extreme polar coordinates on dates with midnight sun or polar night may return unusual or empty windows
- Payment failure or insufficient funds returns a 402 response

## How this service works

Civil, nautical and astronomical twilight boundaries plus golden and blue hour windows for a date and coordinate, in UTC.

## Output

A JSON response containing UTC timestamps for the start and end of civil, nautical, and astronomical twilight, along with golden hour and blue hour windows, all calculated for the specified date and WGS-84 coordinate.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "date",
      "lat",
      "lon"
     ],
     "properties": {
      "lat": {
       "type": "number",
       "description": "Latitude, -90 to 90"
      },
      "lon": {
       "type": "number",
       "description": "Longitude, -180 to 180"
      },
      "date": {
       "type": "string",
       "description": "ISO date YYYY-MM-DD, interpreted in UTC"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fittings-solar-twilight-windows-c137bfa0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fittings.sh](https://www.zero.xyz/host/fittings.sh/llms.txt)