A custom datepicker element based on Google's Material Design built from scratch with lit-element

Usage no npm install needed!

<script type="module">
  import appDatepicker from '';



Datepicker element built with lit-element and Material Design 2

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Version lit-element Node version MIT License

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A different way of datepicker-ing on the web.

💯 Also, featured in awesome-lit-html.

This marks another completion of an important milestone of app-datepicker with all the love from the Web Components community in making this element great and wonderful. As Web Components getting more and more traction and better at providing a web standard way of creating shareable components, it plays an important role in the JavaScript community as many developers depend on a plethora of development tools written in JavaScript for the web to create a better developer experience when developing a library, a component, or even a large scalable application.


Today, app-datepicker has been completely rewritten to adapt to the best of both worlds by leveraging the modern technologies the community most familiar with since year 2018.

The following are the list of tools used that makes it shine:

  1. TypeScript
  2. lit-element

Table of contents


  • ES2019 (The element is compiled with features targeting ES2019, so it might not work properly without transpilation on older browsers.)
  • lit-element >= 2.2.1
  • [OPTIONAL] TypeScript >= 3.8.3 (TypeScript users only)


  • NPM

    $ npm i app-datepicker
  • Alternatively, it can be downloaded from any of the following awesome CDNs:

    1. jsdelivr (ESM)
    2. unpkg (ESM)

How to use


Please make sure you have all these features available on the browsers you are supporting. If no, please consider polyfill-ing in order to run the datepicker element.

The following snippet shows a simple script used in the demo to load polyfills via feature detection on different browsers:

  if (null == Array.prototype.find) {
    Object.defineProperty(Array.prototype, 'find', {
      value: function arrayFind(cb) {
        var filtered = this.filter(cb);
        return !filtered.length ? void 0 : filtered[0];

  if (!window.Intl) {
    var wa = document.createElement('script');
    /** FIXME: Pin package version due to */
    wa.src = '';
    wa.onload = function onLoad() {'🌐 Intl polyfill loaded'); };
    wa.onerror = console.error;


 * Say you've already installed the element via NPM, simply import the package to your application.
 * Here I'm using `lit-element` for developing my application.
import { css, customElement, html, LitElement } from 'lit-element';
import 'app-datepicker';

export class MyApp extends LitElement {
  static is() { return 'my-app'; }

  static styles = [
    :host {
      display: block;

    * {
      box-sizing: border-box;

  protected render() {
    return html`<app-datepicker></app-datepicker>`;


<!doctype html>
  <!-- Using ES modules to load the app -->
  <script type="module" src="/my-app.js"></script>
      <!-- <AppDatepicker> will be rendered when <MyApp> loads. -->

Browser compatibility

Both app-datepicker and app-datepicker-dialog works in last 2 versions of all evergreen browsers (Chrome, Firefox, Edge, and Safari). Internet Explorer 11 is no longer supported in favor of the new Microsoft Edge.

Tested on the following browsers:

Name OS
Chrome 79 Windows 10
Edge 18 Windows 10
Firefox 72 Windows 10
Safari 13 mac 10.13


  1. Does it work well with material-components-web-components?

    For material-components-web-components users, you can create your own custom date picker element by wrapping app-datepicker inside mwc-dialog.

    // Simplified code snippet
    class MWCDatePicker extends LitElement {
      render() {
        return html`
          <mwc-button slot="secondaryAction" dialogAction="cancel">cancel</mwc-button>
          <mwc-button slot="primaryAction" dialogAction="set">set</mwc-button>
  2. How can I hide the focus outline?

    For a11y reason, focus outline is shown when a calendar day is being focused. However, this can be modified via CSS Shadow Parts.

     * Hide focus ring.
     * NOTE: It is recommended to come up with alternative styling for focus state
     * instead of just hiding the focus ring.
    app-datepicker::part(calendar-day):focus {
      outline: none;

API references


Configurable demo powered by Firebase

Older versions

Meantime, feel free to check the older version out at:

  1. 2.x branch - Built with Material Design and Polymer 2, published at Bower.
  2. 3.x branch - Built with Material Design and Polymer 3, published at NPM.


MIT License © Rong Sen Ng