# Time zone and UTC offset at a point

`GET https://api.astroway.info/v1/geo/timezone`

The IANA zone at a point and the UTC offset its clocks kept at that local date and time, from the tz database, never a fixed offset: Kyiv answers +2 in January, +3 in July and +4 on 15 May 1990, when it kept Moscow summer time. `time` defaults to 12:00 and matters on the day clocks change; a skipped hour resolves to the offset from before the change, a repeated one to its first occurrence. `standardOffset` is the smaller of the year's offsets and `isDst` is true when the clock is ahead of it. Before 1970 the tz database is not reliable everywhere: if you know the local clock, send `timezoneOffset` to the chart instead.

Group: Astro-Geography. Auth: `X-Api-Key` header. Operation ID: `geo_timezone_get`.

## Parameters

| Name | In | Required | Type | Description |
|---|---|---|---|---|
| `lat` | query | yes | number | Latitude in decimal degrees, north positive. |
| `lon` | query | yes | number | Longitude in decimal degrees, east positive. |
| `date` | query | no | string | Local calendar date `YYYY-MM-DD` at the point. Defaults to today (UTC). |
| `time` | query | no | string | Local clock time `HH:MM` or `HH:MM:SS`. Matters only on the day clocks change. |
| `fields` | query | no | string | Comma-separated dotted paths, relative to `data`, to keep in the response. A path is applied to every element of an array, so `planets.name` means the name of each planet. Paths that match nothing come back in `_fields_unmatched`; a list where nothing matches at all is a 400, because an empty object would be a confident wrong answer. |
| `precision` | query | no | integer | Round every non-integer number in the response to this many decimal places. Integers are left alone, because an id is not a measurement. Ecliptic longitudes ship with fourteen decimals by default; 2 is about a tenth of an arcminute. |

## Responses

| Status | Meaning |
|---|---|
| 200 | Successful calculation |
| 400 | Validation error |
| 401 | Missing or invalid API key |

### Success fields, under `data`

| Field | Type | Required | Description |
|---|---|---|---|
| `latitude` | number | no |  |
| `longitude` | number | no |  |
| `timezone` | string | no |  |
| `nautical` | boolean | no |  |
| `date` | string | no |  |
| `time` | string | no |  |
| `utcOffset` | number | no |  |
| `utcOffsetText` | string | no |  |
| `standardOffset` | number | no |  |
| `isDst` | boolean | no |  |

## Example

```bash
curl -X GET https://api.astroway.info/v1/geo/timezone?lat=49.8397&lon=24.0297 \
  -H "X-Api-Key: aw_live_..." \
  -H "Content-Type: application/json"
```

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Rendered from https://api.astroway.info/v1/openapi.json. HTML page: https://api.astroway.info/docs/api/operations/geo_timezone_get/