The Google Calendar API is one of Google’s most used APIs. Today, we’re rolling out a new version of the API that will give developers even more reasons to use it. Version three of the Google Calendar API provides several improvements over previous versions of the API:

• Lightweight resource representation in JSON
• Consistent and comprehensive reference documentation
• Improved support for recurring events
• Ability to manipulate default reminders on calendars
• Access to the new UI and event colors

Developers familiar with the Google Tasks API will feel right at home with Calendar API v3, as it uses similar syntax and conventions, as well as the same base client libraries. These Google-supported client libraries, based on discovery, are available in many languages with:

• Straightforward development for mobile using the client libraries for Java and Objective-C
• Native support for OAuth 2.0
• Native partial and PATCH support

If you’re new to the Google Calendar API, getting started is easy. Check out the Getting Started Guide, which will walk you through the basic concepts of Google Calendar, the API, and authorization. Once you’re ready to start coding, the Using the API page will explain how to download and use the client libraries in several languages.

If you’d like to try out some queries before you start coding, check out the APIs Explorer and try out some example queries with the new API.

Developers already using older versions of the API can refer to our Migration Guide. This interactive guide offers side-by-side examples of the API in v2 and v3 flavors across both the protocol and multiple languages. Simply hover over the code in v2 (or v3) and see the equivalent in the other version.

With our announcement of v3 of the API, we’re also announcing the deprecation of the previous versions (v1 and v2). The older versions enter into a three year deprecation period, beginning today, and will be turned off on November 17, 2014.

We’d love to hear your feedback on the Google Calendar API v3. Please feel free to reach out to us in the Google Calendar API forum with any questions or comments you have. We’ll also be hosting live Office Hours (via Google+ Hangout) on 11/30 from 8am-8:45am EST to discuss the new API. We hope to see you then!

Dan Holevoet   profile Dan joined the Google Developer Relations team in 2007. When not playing Starcraft, he works on Google Apps, with a focus on the Calendar and Contacts APIs. He's previously worked on iGoogle, OpenSocial, Gmail contextual gadgets, and the Google Apps Marketplace.

Alain Vongsouvanh   profile Alain is a Developer Programs Engineer for Google Apps with a focus on Google Calendar and Google Contacts. Before Google, he graduated with his Masters in Computer Science from EPITA, France.