Mozilla Sunbird

Mozilla Sunbird is a full featured and easy-to-use calendar extension built upon the Mozilla Toolkit. Is a complete redevelopment of the Mozilla Calendar extension, that was based on Mozilla's XUL user interface. If you use Mozilla Firefox or Mozilla Thunderbird as your default web browser or email client respectively, and you need a calendar application, preferably based on the same Mozilla-technology, you should try this intuitive and useful application.

Mozilla Sunbird can perfectly handle hundred or even thousands of events easily and you can customize it to your needs. The daily calendar shows the full 24 hours, instead of just a 'working' hours, and its reliable alarm will see to it you are notified about any event or task. You can also define multiple alarms for a single event. It features a reliable interoperability with various CalDAV servers, including support for Google Calendar by using an extension.