The Diarian plugin brings robust journaling capabilities to Obsidian, enhancing your note-taking with features like a calendar view, daily note ratings, and an 'On this day' review pane. Users can quickly access daily notes, review previous entries, and even import content from the Diarium app. The plugin supports multiple daily notes, nested note organization, and allows for customizable templates. It also integrates a timestamp feature and lets users convert pre-existing daily notes to a new format. Diarian's unique functionality allows users to track their journaling activities in a visually organized manner, all within Obsidian.