Quickstart

Get up and running with app-datepicker in minutes. This guide walks you through installation, basic setup, and common configuration patterns to have a beautiful Material Design datepicker working in your application quickly.

Installation

First, install app-datepicker using your preferred package manager:

npm install app-datepicker@next

The @next tag installs version 6.x (currently at RC 33), which is the actively developed version with the latest features and improvements.

Basic HTML usage

The simplest way to get started is with a CDN import. No build tools required:

Create an HTML file

Create an index.html file with this basic structure:

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>My Date Picker</title>
  
  <!-- Import from CDN -->
  <script type="module">
    import 'https://esm.run/app-datepicker@next';
  </script>
</head>
<body>
  <h1>Select a Date</h1>
  <app-date-picker></app-date-picker>
</body>
</html>

Add event handling

Listen for date selection and display the value:

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>My Date Picker</title>
  
  <script type="module">
    import 'https://esm.run/app-datepicker@next';
    
    window.addEventListener('DOMContentLoaded', () => {
      const picker = document.querySelector('app-date-picker');
      const output = document.getElementById('selected-date');
      
      picker.addEventListener('date-updated', (event) => {
        const { value, valueAsDate, valueAsNumber } = event.detail;
        output.textContent = `Selected: ${value} (${valueAsDate.toLocaleDateString()})`;
      });
    });
  </script>
</head>
<body>
  <h1>Select a Date</h1>
  <app-date-picker 
    min="2024-01-01" 
    max="2024-12-31"
    value="2024-03-15"
  ></app-date-picker>
  
  <p id="selected-date">Selected: 2024-03-15</p>
</body>
</html>

Open in browser

Open the file in your browser and you’ll see a fully functional Material Design datepicker!

Usage with a bundler (npm/yarn/pnpm)

For production applications, use app-datepicker with a module bundler like Vite, Webpack, or Rollup.

Install dependencies

npm install app-datepicker@next lit

Import and use in TypeScript/JavaScript

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';
import 'app-datepicker';

@customElement('my-app')
export class MyApp extends LitElement {
  static styles = css`
    :host {
      display: block;
      padding: 20px;
    }
    
    app-date-picker {
      margin: 20px 0;
    }
  `;

  @state()
  private selectedDate = '2024-03-15';

  private handleDateUpdate(e: CustomEvent) {
    const { value, valueAsDate } = e.detail;
    this.selectedDate = value;
    console.log('Date selected:', value, valueAsDate);
  }

  render() {
    return html`
      <h1>Choose Your Date</h1>
      
      <app-date-picker
        .value=${this.selectedDate}
        min="2024-01-01"
        max="2024-12-31"
        @date-updated=${this.handleDateUpdate}
      ></app-date-picker>
      
      <p>Selected date: ${this.selectedDate}</p>
    `;
  }
}

Configure your bundler

Ensure your bundler is configured to handle ES modules. For Vite:

vite.config.js

import { defineConfig } from 'vite';

export default defineConfig({
  build: {
    target: 'es2021',
  },
});

Component variants

app-datepicker provides three component variants for different use cases:

date-picker

Inline calendar component for embedding directly in your UI

date-picker-input

Material Design text field with integrated datepicker dropdown

date-picker-dialog

Modal dialog containing the datepicker

Using date-picker-input

Perfect for form fields:

import 'app-datepicker/app-date-picker-input';

// In your HTML/template
<app-date-picker-input
  label="Date of Birth"
  placeholder="Select your date of birth"
  value="2024-03-15"
  min="1900-01-01"
  max="2024-12-31"
  outlined
></app-date-picker-input>

Using date-picker-dialog

Great for mobile experiences:

import 'app-datepicker/app-date-picker-dialog';

// Show the dialog
const dialog = document.querySelector('app-date-picker-dialog');
dialog.show();

// Listen for dialog events
dialog.addEventListener('closing', (event) => {
  const action = event.detail.action; // 'set', 'cancel', or 'reset'
  if (action === 'set') {
    console.log('Date confirmed:', dialog.value);
  }
});

Common configuration patterns

Date constraints

Restrict selectable dates with min and max:

<app-date-picker
  min="2024-01-01"
  max="2024-12-31"
  value="2024-06-15"
></app-date-picker>

Disabling specific dates

Disable weekends and specific dates:

<app-date-picker
  value="2024-03-15"
  disabledDays="0,6"
  disabledDates="2024-03-20,2024-03-21,2024-03-25"
></app-date-picker>

disabledDays: 0 = Sunday, 1 = Monday, …, 6 = SaturdaydisabledDates: Comma-separated list of dates in YYYY-MM-DD format

Internationalization

Set the locale for proper date formatting and first day of week:

<app-date-picker
  locale="de-DE"
  firstDayOfWeek="1"
  value="2024-03-15"
></app-date-picker>

Week numbers

Display ISO week numbers:

<app-date-picker
  value="2024-03-15"
  showWeekNumber
  weekNumberType="first-4-day-week"
></app-date-picker>

Start view

Control which view shows first - calendar or year grid:

<app-date-picker
  value="2024-03-15"
  startView="calendar"
></app-date-picker>

The year grid view is perfect for date of birth pickers where users need to select a year first.

Event handling

All components emit these events:

date-updated

Fired when a date is selected:

picker.addEventListener('date-updated', (event) => {
  const { 
    value,        // '2024-03-15' (ISO string)
    valueAsDate,  // Date object
    valueAsNumber,// Unix timestamp (ms)
    isKeypress,   // true if selected via keyboard
    key           // Key name if keyboard selection
  } = event.detail;
  
  console.log('Selected date:', value);
});

first-updated

Fired once when the component first renders:

picker.addEventListener('first-updated', (event) => {
  const { value, valueAsDate, valueAsNumber, focusableElements } = event.detail;
  console.log('Picker initialized with:', value);
});

Complete working example

Here’s a complete example with multiple features:

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';
import 'app-datepicker';

@customElement('vacation-planner')
export class VacationPlanner extends LitElement {
  static styles = css`
    :host {
      display: block;
      max-width: 400px;
      margin: 40px auto;
      padding: 24px;
      background: #f5f5f5;
      border-radius: 8px;
    }
    
    h1 {
      margin-top: 0;
      color: #333;
    }
    
    app-date-picker {
      margin: 20px 0;
      
      /* Custom theme colors */
      --app-primary: #1976d2;
      --app-on-primary: #ffffff;
      --app-surface: #ffffff;
    }
    
    .info {
      padding: 16px;
      background: white;
      border-radius: 4px;
      margin-top: 16px;
    }
    
    .info p {
      margin: 8px 0;
      color: #666;
    }
  `;

  @state()
  private startDate = '';
  
  @state()
  private daysUntil = 0;

  private handleDateSelect(e: CustomEvent) {
    const { value, valueAsDate } = e.detail;
    this.startDate = value;
    
    // Calculate days until vacation
    const today = new Date();
    const vacation = valueAsDate;
    const diff = Math.ceil((vacation.getTime() - today.getTime()) / (1000 * 60 * 60 * 24));
    this.daysUntil = diff;
  }

  render() {
    const today = new Date().toISOString().split('T')[0];
    const nextYear = new Date();
    nextYear.setFullYear(nextYear.getFullYear() + 1);
    const maxDate = nextYear.toISOString().split('T')[0];

    return html`
      <h1>Plan Your Vacation</h1>
      
      <app-date-picker
        .value=${this.startDate || today}
        .min=${today}
        .max=${maxDate}
        locale="en-US"
        showWeekNumber
        disabledDays="0,6"
        @date-updated=${this.handleDateSelect}
      ></app-date-picker>
      
      ${this.startDate ? html`
        <div class="info">
          <p><strong>Vacation Start:</strong> ${this.startDate}</p>
          <p><strong>Days Until:</strong> ${this.daysUntil} days</p>
          ${this.daysUntil < 0 ? html`
            <p style="color: #d32f2f;">This date has passed!</p>
          ` : ''}
        </div>
      ` : html`
        <div class="info">
          <p>Select your vacation start date</p>
        </div>
      `}
    `;
  }
}

Value formats

app-datepicker provides three ways to work with date values:

const picker = document.querySelector('app-date-picker');

// Set value (ISO string format: YYYY-MM-DD)
picker.value = '2024-03-15';

// Get value as ISO string
console.log(picker.value); // '2024-03-15'

// Get value as Date object
console.log(picker.valueAsDate); // Date object

// Get value as Unix timestamp (milliseconds)
console.log(picker.valueAsNumber); // 1710460800000

The value property must always be in YYYY-MM-DD format. Invalid formats will be rejected and the previous valid value will be retained.

Styling

Customize the appearance using CSS custom properties:

app-date-picker {
  /* Primary color - selected date */
  --app-primary: #6200ee;
  --app-on-primary: #ffffff;
  
  /* Surface colors - background */
  --app-surface: #ffffff;
  --app-on-surface: #000000;
  
  /* Hover and focus states */
  --app-hover: #f3e5f5;
  --app-focus: #7c4dff;
  
  /* Today indicator */
  --app-today: #1976d2;
  --app-on-today: #ffffff;
}

Next steps

Now that you have a working datepicker, explore more advanced features:

API Reference

Explore all properties, methods, and events for app-date-picker

Styling Guide

Learn how to customize colors, spacing, and themes

Input Component

Use the date picker with a Material Design text field

Dialog Component

Display the date picker in a modal dialog

Check out the live demo to see all features in action with configurable code snippets.

Get Started

Guides

Migration

Quickstart

Quickstart

Installation

Basic HTML usage

Usage with a bundler (npm/yarn/pnpm)

Component variants

date-picker

date-picker-input

date-picker-dialog

Using date-picker-input

Using date-picker-dialog

Common configuration patterns

Date constraints

Disabling specific dates

Internationalization

Week numbers

Start view

Event handling

date-updated

first-updated

Complete working example

Value formats

Styling

Next steps

API Reference

Styling Guide

Input Component

Dialog Component

Get Started

Guides

Migration

​Quickstart

​Installation

​Basic HTML usage

​Usage with a bundler (npm/yarn/pnpm)

​Component variants

date-picker

date-picker-input

date-picker-dialog

​Using date-picker-input

​Using date-picker-dialog

​Common configuration patterns

​Date constraints

​Disabling specific dates

​Internationalization

​Week numbers

​Start view

​Event handling

​date-updated

​first-updated

​Complete working example

​Value formats

​Styling

​Next steps

API Reference

Styling Guide

Input Component

Dialog Component

Quickstart

Installation

Basic HTML usage

Usage with a bundler (npm/yarn/pnpm)

Component variants

Using date-picker-input

Using date-picker-dialog

Common configuration patterns

Date constraints

Disabling specific dates

Internationalization

Week numbers

Start view

Event handling

date-updated

first-updated

Complete working example

Value formats

Styling

Next steps