Adding a fully-featured calendar to your website or application allows users to view, create and manage events and dates. But coding one from scratch requires significant development effort. That’s where Javascript calendar libraries come in handy. These pre-built sets of Javascript code provide the foundations and tools to quickly integrate calendar functionality.

In this article, we’ll explore some of the most popular Javascript calendar libraries like React-Calendar and Kendo UI. We’ll also walk through how to build a custom calendar yourself using HTML, CSS and Javascript. And we’ll cover tips for integrating and optimizing calendar performance. Let’s dive in!

Benefits of Javascript Calendar Libraries

Here are some of the key advantages of using a library:

• Speeds up development time by handling complex calendar logic out of the box
• Provides features like date validation, localization, custom rendering and more
• Allows styling and customizing the calendar’s design and interactivity
• Simplifies cross-device compatibility, ensuring calendars work on both desktop and mobile
• Takes care of updates and maintenance as new versions are released

Popular Javascript Calendar Libraries

React-Calendar

React-Calendar is a great choice for React-based projects. After installing via npm, import the Calendar and CalendarTile components:

import { Calendar, CalendarTile } from 'react-calendar'; 

Render the Calendar component and pass events data through a prop. Customize rendering and styling using other props:

<Calendar
  events={events}
  tileContent={({ date, view }) => (
    view === 'month' && <CalendarTile />      
  )}
  tileDisabled={({ date }) => date.getDay() === 0} 
  styles={{color: 'blue'}}
/>

Kendo UI Calendar

Kendo UI offers a jQuery-based calendar widget. Reference the stylesheet and JavaScript, then initialize the calendar on a div:

<div id="calendar"></div>

$("#calendar").kendoCalendar({
  weekNumber: true,
  footer: 'Today',
  events: [
    // events 
  ]  
});

Use options like weekNumber and footer to customize. Define events through the events array.

FlexCalendar

FlexCalendar is a lightweight component. Import and supply events through a prop:

import FlexCalendar from 'flexcalendar';

<FlexCalendar
  events={events}
  color={'#0088cc'}
  selection={'range'}
  onClick={handler}
/>

Customize with color, selection, onClick handler, and more.

Limitations of Libraries

While helpful in many cases, some downsides exist with libraries:

• Reliance on Javascript can cause compatibility issues in non-JS environments
• Large libraries can slow page load times and performance
• Limited ability to deeply customize design and functionality
• Bug fixes and updates are dependent on library maintainers
• Steep learning curve for those newer to Javascript

Creating a Custom Javascript Calendar

For full customization and flexibility, building your own calendar from the ground up is an option. Here are the key steps:

1. Initialize a project and install tools like Node.js and webpack
2. Build HTML markup for the calendar structure
3. Write Javascript display logic for elements like the month header and day grid
4. Enable navigation between months and years
5. Implement a data model for events with interaction logic
6. Allow UI interactions like clickable days and drag-and-drop
7. Write tests and refine the library API
8. Optimize performance through strategies like minification
9. Package and distribute the finished library

Complementary Tools

HTML provides the semantic calendar structure. CSS handles all styling and responsiveness. jQuery simplifies DOM manipulation compared to plain Javascript.

Calendar Alternatives

For those wanting to avoid Javascript, some alternatives include:

• Server-side calendars built with PHP, Ruby or Python
• Leveraging the Google Calendar API
• Using native calendars from mobile operating systems
• Evaluating other JS libraries like FullCalendar.js

Integrating Javascript Calendars

To integrate your calendar into an HTML page:

1. Add the Javascript code directly into the HTML document
2. Link to a container element like a <div> where the calendar will live
3. Adjust sizing, styling and other options as needed
4. Attach custom data attributes to calendar events

Optimizing Performance

Follow these tips to optimize calendar performance:

• Minify Javascript code to reduce file size
• Split code into separate files and load only as needed
• Test thoroughly across browsers to catch issues
• Follow UX best practices to ensure an intuitive interface

Conclusion

Javascript calendar libraries provide convenience. But those wanting maximum control and customization may instead consider building their own from scratch. Complementary technologies like HTML, CSS and jQuery play key roles in development. And alternatives like server-side calendars exist for non-Javascript environments.

Related Contents

• Kendo Javascript: Javascript Explained
• Event Calendar Java Script: Java Explained
• Calendar Javascript Library: Javascript Explained
• Calendar Library Javascript: Javascript Explained
• Javascript Calendar Code: Javascript Explained