Header showing a localized month name and the year
Demo: A default representation of the month and year in browser's default locale


Given a reference date property, this component will show a calendar representation of that month and year.

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

CalendarMonth instantiates CalendarMonthYearHeader to show the name of the current month and the year as a header for the calendar month.


Ancestry: CalendarMonthYearHeader → ReactiveElement → HTMLElement

Built with mixins AttributeMarshallingMixin, CalendarElementMixin, ReactiveMixin, 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

date property

The date that should be shown by the element. For elements that show a range of dates (a month, a week, etc.), the referenced date will be included in the range.

This property can be set as a string, which will be parsed and converted to a JavaScript Date.

If not specified, the default date value is the current date.

Type: Date|string

Defined by CalendarElementMixin

date-changed event

Raised when the date property changes.

Defined by CalendarElementMixin

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

locale property

A string that identifies a language and a region using a BCP 47 language tag. This is the same format used by to identify a locale in the standard Intl internationalization API. See the locales argument documentation for details.

Calendar elements are region-sensitive, so language alone is insufficient. Accordingly, the locale should identify at least a language and a region. Examples: "en-US" identifies US English, while "en-GB" identifies English in Great Britain. The use of "en" on its own would be insufficient.

Type: string

Defined by CalendarElementMixin

monthFormat property

The format used to render the month name.

The allowable formats are the same as the month formats in Intl.DateTimeFormat.

Type: 'numeric'|'2-digit'|'long'|'short'|'narrow'

Default: 'long'

render() method

Render pending component changes 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

state property

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

Type: State

Defined by ReactiveMixin

[symbols.render](changed) method

Internal method for rendering any recent changes in state to the DOM.

The default implementation of this method does nothing. Override this method in your component to update your component's host element and any shadow elements to reflect the component's new state. See the rendering example.

Be sure to call super in your method implementation so that your component's base classes and mixins have a chance to perform their own render work.


  • changed: objectdictionary of flags indicating which state members have changed since the last render

Defined by ReactiveMixin

yearFormat property

The format used to render the year.

The allowable formats are the same as the year formats in Intl.DateTimeFormat.

Type: 'numeric'|'2-digit'

Default: 'numeric'