Header showing the localized days of the week
Demo: A default representation of day names in browser's default locale


All of the Elix calendar components attempt to provide full international calendar support to the extent currently possible in the user's web browser.

In the case of this component, it will show the appropriate names of the days of the week for a specific locale (or, by default, the user's current locale). The day(s) associated with the weekend in that locale will also be indicated. It will also correctly reflect the typical first day of the week for that locale. Example: U.S. calendars typically start with Sunday as the first day of a week, while British calendars typically start with Monday as the first day.


Ancestry: CalendarDayNamesHeader → ReactiveElement → HTMLElement

Built with mixins AttributeMarshallingMixin, ReactiveMixin, RenderUpdatesMixin, and ShadowTemplateMixin.

$ property

A convenient shortcut for looking up an element by ID in the component's Shadow DOM subtree.

Example: if component's template contains a shadow element <button id="foo">, you can use the reference this.$.foo to obtain the corresponding button in the component instance's shadow tree. The $ function is simply a shorthand for getElementById, so this.$.foo is the same as this.shadowRoot.getElementById('foo').

Type: object

Defined by ShadowTemplateMixin

defaultState property

The default state for the component. This can be extended by mixins and classes to provide additional default state.

Type: State

Defined by ReactiveMixin

format property

The format used to render the day names.

Type: 'long'|'narrow'|'short'

Default: 'short'

locale property

A string that identifies a language and a region using a BCP 47 language tag. This works the same as the CalendarElementMixin locale property.

Type: string

render() method

Render the component to the DOM.

This method does nothing if the state has not changed since the last render call.

This method invokes all internal render methods. It then invoked componentDidMount (for first render) or componentDidUpdate (for subsequent renders).

Defined by ReactiveMixin

setState(changes) method

Update the component's state by merging the specified changes on top of the existing state. If the component is connected to the document, and the new state has changed, this returns a promise to asynchronously render the component. Otherwise, this returns a resolved promise.


  • changes: objectthe changes to apply to the element's state

Returns: Promise - resolves when the new state has been rendered

Defined by ReactiveMixin

shouldComponentUpdate(nextState) method

Return true if the component should update.

By default, ReactiveMixin will perform a shallow check of property values like React's PureComponent. This seems adequate for most web components. You can override this to always return true (like React's base Component class), or to perform more specific, deeper checks for changes in state.


  • nextState: Statethe proposed new state for the element

Returns: boolean - true if the component should update (rerender)

Defined by ReactiveMixin

state property

The component's current state. The returned state object is immutable. To update it, invoke setState.

Type: State

Defined by ReactiveMixin

updates property

The attributes and properies that should be applied to the component on render. By default, this is an empty plain object. Your mixin or component can extend this to identify the properties to set on the host element or elements in the shadow subtree.

Type: object

Defined by RenderUpdatesMixin