Google Calendar is a time-management and scheduling calendar service developed by Google. It became available in beta release on April 13, 2006, and in general release on July 2009, on the web and as mobile apps for the Android and iOS platforms.
Sunbird is a cross-platform calendar application. It is part of the Mozilla Application Suite and uses the ICS file format. Sunbird is free and open-source software released under the Mozilla Public License. Sunbird has been succeeded by the Lightning calendar extension for Mozilla Thunderbird. Sunbird can be used to manage multiple calendars, both online and offline. It can synchronize with Google Calendar, Yahoo! Calendar, and other online calendar services.
The sunbird google calendar services is a great way to keep track of your appointments and events. It is easy to use and you can access it from anywhere.