JEvents (Events Calendar) consists of a Joomla component and a number of modules and mambots. Collectively you can create one-off or repeating events under various events categories.
JCal Pro is a multi-language events calendar component for Joomla. Its front-end display is CSS-based and really nice. Its features include using native Joomla permissions for event creation/management and viewing, multiple calendars including private or public calendars, WYSIWYG event descriptions, back-end event management, captcha, search plugin, mini-calendar and latest events modules, RSS feeds, SEF URL support and Community Builder plugins.
EventList is not exactly a calendar but an extremely helpful software that will allow you to manage and present events on your Joomla website. EventList includes many features like venue database, picture resizing, simple registration system, map service links and submission of new events and venues from the frontend for your website visitors.