# LocaleConfig

interface

The locale configuration.

```typescript
ClassicEditor
	.create( {
		locale: {
			// The localization configuration.
		}
	} )
	.then( ... )
	.catch( ... );
```

See [all editor configuration options](module_core_editor_editorconfig-EditorConfig.md).

<a id="properties">

## Properties

<a id="member-dateTimeFormat">

### `dateTimeFormat?: ( date: Date, t: LocaleTranslate ) => string`

A function that formats date to the custom format. It is used in dates in annotations (balloons) displaying comments and suggestions details.

The default formatting can be changed by setting a custom formatting function to `config.locale.dateTimeFormat`.

```typescript
import { DateTime } from 'luxon';

ClassicEditor
	.create( {
		attachTo: document.querySelector( '#editor' ),
		toolbar: {
			items: [ 'bold', 'italic', '|', 'comment' ]
		},
		sidebar: {
			container: document.querySelector( '#sidebar' )
		},
		locale: {
			dateTimeFormat: date => DateTime.fromJSDate( date ).toFormat( 'dd/LL/yyyy' )
		}
	} )
	.catch( error => console.error( error ) );
```

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Full index of the CKEditor 5 API reference: [llms.txt](llms.txt)