On This Day by Room 34 is a free WordPress widget designed to enhance blog engagement by showcasing past posts published on the same date in previous years. This tool is particularly useful for bloggers looking to remind their audience of historical content, thus driving traffic to older posts. The widget offers several customization options, allowing users to personalize the title, display messages for days without posts, and set a maximum number of posts to show. Additionally, it can display featured images if available, providing a visually appealing experience.

The widget also includes category filtering to ensure that only relevant posts are shown, making it easier for users to navigate through content. A notable feature introduced in version 2.0 is the optional On This Day archive page, which organizes historical posts in a dedicated section. However, to utilize this feature, users need to ensure their theme is compatible with the necessary archive functions.