| tz | No | IANA timezone like "Europe/Lisbon" to render event times in local time. Optional; a resolved place supplies its own timezone. | |
| end | No | Last day of a daily series. ISO 8601 UTC date or datetime, e.g. "2026-08-06" or "2026-08-06T21:00:00Z". Omit for the current moment. Years 1700 to 2200 only; outside that range the API refuses with DATE_OUT_OF_RANGE because the ephemeris is not reliable there. | |
| lat | No | Latitude in decimal degrees, north positive. Send lat and lon together. | |
| lon | No | Longitude in decimal degrees, east positive (Lisbon is about -9.14). Send lat and lon together. | |
| body | Yes | One of sun, moon, mercury, venus, mars, jupiter, saturn, uranus, neptune, pluto, or a fixed J2000 target as "radec:RA,DEC" with RA in hours (0-24) and DEC in degrees (-90..90), e.g. "radec:5.6,-5.4" for the Orion Nebula region. | |
| date | No | ISO 8601 UTC date or datetime, e.g. "2026-08-06" or "2026-08-06T21:00:00Z". Omit for the current moment. Years 1700 to 2200 only; outside that range the API refuses with DATE_OUT_OF_RANGE because the ephemeris is not reliable there. | |
| place | No | Place name instead of lat/lon, as "City" or "City,CC" with an ISO country code, e.g. "Lisbon,PT". Resolved server-side; the response then carries a required GeoNames CC BY 4.0 credit in its attribution field, which must be preserved when shown. | |
| start | No | First day of a daily series. ISO 8601 UTC date or datetime, e.g. "2026-08-06" or "2026-08-06T21:00:00Z". Omit for the current moment. Years 1700 to 2200 only; outside that range the API refuses with DATE_OUT_OF_RANGE because the ephemeris is not reliable there. | |
| cursor | No | Opaque pagination cursor from a previous result's next_cursor. Send it with the same start/end arguments as the first page. | |
| search_horizon_days | No | How many days ahead to search when an event does not occur on the requested day (high latitudes). | |