> Documentation index: https://www.gooddata.ai/docs/gooddata-ui/llms.txt lists every page of these docs as Markdown.

# isValidIanaTimezoneId()

- Package: [@gooddata/sdk-model](https://www.gooddata.ai/docs/gooddata-ui/latest/api-reference/sdk-model/index.md)
- Kind: function
- Stability: alpha
- Source: https://github.com/gooddata/gooddata-ui-sdk/blob/rel/11.64/libs/sdk-model/src/dashboard/dashboard.ts

> **Alpha API.** Initial API, highly likely to change outside SemVer. Don't build on it in production. See [API maturity](https://www.gooddata.ai/docs/gooddata-ui/latest/integrations/platform/api-maturity/index.md).
> 

Tests whether `timezoneId` is a valid IANA timezone identifier according to the runtime ICU data (via `Intl.DateTimeFormat`). The [BROWSER\_DETECTED](https://www.gooddata.ai/docs/gooddata-ui/latest/api-reference/sdk-model/sdk-model.browser_detected/index.md) sentinel is not a valid IANA ID — use [isValidDashboardTimezoneId()](https://www.gooddata.ai/docs/gooddata-ui/latest/api-reference/sdk-model/sdk-model.isvaliddashboardtimezoneid/index.md) for values stored on the dashboard.

Identifiers are case-sensitive. `Intl` accepts timezones case-insensitively, so a value that only differs in case from the canonical form (e.g. `"america/new_york"`) is rejected. Aliases that resolve to a different identifier (e.g. `"Etc/UTC"` → `"UTC"`) are still accepted as ICU-known IDs. Offset-style identifiers (e.g. `"+01"`, `"+0100"`, `"+01:00"`) are rejected.

**Signature:**

```typescript
export declare function isValidIanaTimezoneId(timezoneId: string): boolean;
```

## Parameters

| Parameter | Type | Description |
| --- | --- | --- |
| timezoneId | string | timezone identifier to test |

**Returns:**

boolean