Kalender is a straightforward calendar and ToDo application with a solid set of features and an easy to use interface. It provides weekly, monthly and yearly views, and allows you to create simple or recurring reminders with optional alarm and custom color choice. Events can also be associated with a document, or launch a command. Kalender can optionally export selected calendar views to CSV or nicely formatted HTML (based on customizable templates). Additional features includes customizable snooze settings, custom event categories, hidden events, integrated backup and more.
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I like it. It's straight forward, no fancy stuff and it's warns me when I need to do something. It is not fantastic but it works.